Computer at parts store says 4mm after 1-15-98. Mine is 12-97 so 3mm. BUT... Was the thicker gasket Ford's answer to the problem? If so, then wouldn't it seem right to use the 4mm in all cases?

What I have been told, and also read, is that if the heads have been serviced (head to block surface, at the head gasket), then the 4mm size is to be used, as the gap will be bigger due to the material removed during the the smoothing of the head surface.
So, if the head gaskets have not been replaced, use the 3mm size....if that is what is called for.
The computer at the dealership, for my '96 3.8L said to use 3mm if the heads have not been serviced, and 4mm if the heads have been off.

I would get the replacement gaskets from FORD as they have made improvements to them.....that likely have not made it to the aftermarket gaskets yet.....also, their computer should be the most accurate as to what to use.....for your year / engine.
It will cost about $50 (List price) for the genuine FORD parts....which is very little as compaired to all the work involved.

Also, make sure to torque the lower intake manifold manifold bolts to the correct specification, in the correct order.

You will also need to change the oil and filter before running the engine, as there is no way to avoid getting coolant into the oil when replacing the lower intake manifold gaskets.

My '96 had one of those "quick connect" connectors on that heater hose, where it connects to the lower intake manifold.
Mine fell apart, even when I used the special removal tool (autozone).
I ended up cutting it off and pushing the hose onto the nipple, and using a regular hose clamp.
I think that mine would use a 3/4" connector......so you might want to get the repair kit for yours when you buy your parts.....if they still used that in '98.

I have some pictures of the process in my pictures.

I replaced my intake manifold gaskets on my '98 3.8L and they still leak. I'm pretty sure I got the 3mm set, from AZ. I went by the manufacture date when choosing and I don't know what service it's previously had since I bought it used.

I've been trying to rid myself of the evil 171/174 codes and I was searching for a leak with a can of throttle body cleaner. The engine revs up when I spray around the block and lower manifold.

I'm begining to suspect it's the wrong sized gaskets and am considering trying the 4mm set, from Ford.

:banghead:

Hi
Sorry you are having trouble. I did the job on my '96 last week. The OEM manual calls for 71-106 IN-LBS of torque on the lower bolts which is not all that much. I chose to use 96 as my target. I first tightened them in order to just over finger tight. I then torqued in order to 92, and then went back around going to 96. On the second pass, a few of the nuts, those in the center near the base of the intake ports were fairly loose, and snugged up nicely to 96.
With all that said, might I suggest you pull the upper off and re-torque first to see what you get? By the way, did you use the thread sealant? I believe its primary purpose is maintaning the bolts in place on torque.

Good luck

I did use the sealant but maybe I didn't use enough. I went back to check the bolts and found that some were a little loose. I'm affraid to get that stuff where it doesn't need to be. Can I use too much? Should I slop it on the bolt really good or will a thin coat in the threads do? Same question for the gasket sealant.

Would it hurt to use the thicker gasket? Or am I crazy thinking that could cause the leak?

I did use the sealant but maybe I didn't use enough. I went back to check the bolts and found that some were a little loose. I'm affraid to get that stuff where it doesn't need to be. Can I use too much? Should I slop it on the bolt really good or will a thin coat in the threads do? Same question for the gasket sealant.

Would it hurt to use the thicker gasket? Or am I crazy thinking that could cause the leak?

Hi
I don't think you need to go too crazy on the thread sealant. The Ford sealant I used directed you to not goop the first few threads. My bolts had previously had a red sealant on them and so I just put it where the old was. As to the gasket sealant for the corners, I think that is more for oil seepage, as any air drawn in at that point would have to get past the gasket where it "circles" the individual intake ports. Don't you think?

I certainly don't think you are crazy for thinking about the thicker gaskets, just wanted to encourage simpler options first.

Good Luck

Don't over-do the goo......more is NOT better.
Too much will oozz all over.....and can cause leaks.
The lower intake manifold is NOT to have any stuff put on it.....you fit it dry.

If you remove the lower intake manifold again......you need to use new lower intake manifold gaskets.
It is possible that the dealer may have different information for your '98 than for my '96.
If you end up having to do the job again (super worst case), I would get the gaskets from the dealer.....and go by what their parts computer recommends....as that should be the latest information.

Don't over-do the goo......more is NOT better.
Too much will oozz all over.....and can cause leaks.
The lower intake manifold is NOT to have any stuff put on it.....you fit it dry.

I used a little on the two (front and back?) spacers between the two gaskets on the lower, but not on the left and right intake gaskets. I was thinking maybe I should have used some sealant and that was why it was leaking, I guess not.

If you remove the lower intake manifold again......you need to use new lower intake manifold gaskets.
It is possible that the dealer may have different information for your '98 than for my '96.
If you end up having to do the job again (super worst case), I would get the gaskets from the dealer.....and go by what their parts computer recommends....as that should be the latest information.

I will go see what the local dealer says and hopefully they will confirm my 4mm theory.

I'll do it again, it'll be a breeze since I know how now. Like you warned in another post, I broke that plastic heater hose clip and I need to get it off, every now and then I have my own James Bond smoke screen. I think the thermostat has gone bad since I cleaned it also. I'll probably replace the two sensors (engine temp and coolant temp?) just to cover all the bases, they're cheap.

I'm pretty confident I need the thicker gasket, I'm going back under the hood Friday morning, hopefully I will report back with no codes and a shiney new 2007 tag.

Oh, one more question...

My torque wrench only has ft/lbs and the manual torque is in in/lbs, can I simply divide by 12? For example does 120 in/lbs = 10 ft/lbs? I think I came up with about 8 ft/lbs for the manifold bolts.

Lord knows how many times logical thinking has gotten me into trouble, sorry if that's a stupid question. And thanks again for the tips.

Hi

foot pounds divided by 12, or inch pounds times .083. My OEM manual shows 71-106 in-lbs which yields 5.83 - 8.83 ft-lbs. For the lower and upper intake bolts.

I installed the 4mm gaskets and the 0171 & 1074 codes are still there but it doesn't appear to be leaking anymore. That engine is so clean the Virgin Mary herself would be proud to drive this minivan.

I took the battery cables completely off for several hours to make new ones and cleared the codes with my cheap little code reader.

Is it possible that these codes lingered through all of that? when the code first came up it said "PD" which means "previously detected". How would it know the codes were there before if I cleared the codes?

Do I need to take it to the dealer to flash program the PCM?

Could the non-functional A/C mode switch have anything to do with this?

:banghead:

Non-functional A/C mode switch?.....if you are talking about the switch that you set for A/C, Heat, Defrost, etc.....and it is in defrost mode all the time.....then YES it certainly can cause lean codes.

That switch is vaccum actuated....... the source of vaccum is a vaccum line that connects to the back side of the upper intake manifold (many connections back there).
This connection is on the passenger side 'ish.
That is a prime suspect as you had the upper intake manifold off......and it is so easy to miss a connection.

The vaccum then goes to a reserve "box" that is located near the top of the strut, on the passenger side......close to the firewall.
Then a vaccum line passes through the firewall into the passenger compartment.
The A/C and heat airflow selection "door" is located up under the dash.....behind the glove box.

Anyhow.....a disconnected vaccum line to that function = a vaccum leak......

If it is the "blend" door, the one that the temperature control adjustment moves....then that is electrical.....and should not cause any lean codes

Non-functional A/C mode switch?.....if you are talking about the switch that you set for A/C, Heat, Defrost, etc.....and it is in defrost mode all the time.....then YES it certainly can cause lean codes.

That's the switch.

That switch is vaccum actuated....... the source of vaccum is a vaccum line that connects to the back side of the upper intake manifold (many connections back there).
This connection is on the passenger side 'ish.
That is a prime suspect as you had the upper intake manifold off......and it is so easy to miss a connection.

I was very carefull taking the manifold off, since it was the second time. I've checked all the lines coming off the manifold and replaced the large ones. So my guess would be either the switch itself or the lines connected to it. I've replaced that switch before. I might just try replacing it, I sure do hope that finnally fixes it... and I don't have to keep buying a switch every year.

Maybe I'll buy two, one for summer and one for winter. :p

Thanks for the advice.

The vaccum then goes to a reserve "box" that is located near the top of the strut, on the passenger side......close to the firewall.
Then a vaccum line passes through the firewall into the passenger compartment.
The A/C and heat airflow selection "door" is located up under the dash.....behind the glove box.

Anyhow.....a disconnected vaccum line to that function = a vaccum leak......

If it is the "blend" door, the one that the temperature control adjustment moves....then that is electrical.....and should not cause any lean codes[/quote]

I disconnected the line going from the intake plenum to the "reserve" and plugged it and cleared the codes. It went into a "T" which went to the reserve and back through the firewall.

I drove it about two blocks, to the Kroger to get some lunch and back to the office and no codes yet. If they don't come back on my way home I guess I can assume the leak is in either the reserve box, the "T", the line going through the firewall to the switch, or the switch itself. I'll work the plug down the line and if I get to the end of the line that connects to the switch I guess the switch is bad. They've got one in stock at my local dealer for $26 amazingly enough.

The codes came back, maybe the line I plugged was the culpret. I got some little vacuum caps from AZ, I'm going to block it at the intake plenum and see if that does it.

I think it would be simpler just to replace all the vacuum lines.

:banghead:

Hi
Do you have a hand vacuum pump? I have used it extensively to check for vacuum leaks on these lines and it really is great. If you do want to, I just today took out all the vacuum lines as an assembly. If you detach them all at the back of the plenum, the yellow one going to the evap canister, the red one up to the A/c system, the shielded one up to the EGR valve, the IMRC's and fuel pressure regulator, and finally the red/black at the right fender, you can gently manuever the whole assembly out of the engine compartment. I was then able to use my vacuum pump to check individual lines for leaks. I had an old repair on the red A/c line that was leaky - not too bad so I re-did it. Anyway, if you keep everything in the same position it all goes right back.
I did have the cowl off for the job.
I have a new IMRC solenoid, and an actuator on the way. Should be in good shape then. Van runs great with the IMRC system "blocked" out for now.

By the way, the IMRC actuator was only $71 at Rockauto.com.

Good luck

Hi
Do you have a hand vacuum pump? I have used it extensively to check for vacuum leaks on these lines and it really is great.

No, but I do have a vacuum gauge.

If you do want to, I just today took out all the vacuum lines as an assembly. If you detach them all at the back of the plenum, the yellow one going to the evap canister, the red one up to the A/c system, the shielded one up to the EGR valve, the IMRC's and fuel pressure regulator, and finally the red/black at the right fender, you can gently manuever the whole assembly out of the engine compartment. I was then able to use my vacuum pump to check individual lines for leaks. I had an old repair on the red A/c line that was leaky - not too bad so I re-did it. Anyway, if you keep everything in the same position it all goes right back.
I did have the cowl off for the job.
I have a new IMRC solenoid, and an actuator on the way. Should be in good shape then. Van runs great with the IMRC system "blocked" out for now.

By the way, the IMRC actuator was only $71 at Rockauto.com.

Good luck

Wow, that's a great price on the IMRC... I've come to the conclusion that I'm just going to replace vacuum lines and connectors until it goes away.

I'll start with the EGR line. I'm really poor right now, I just switched jobs and we're barely eating. (Don't worry, I have a great job now with Honeywell, but when it rains it pours, ya know? Now that the house isn't going to be sold on the courthouse steps I can concentrate on the GD vehicle emissions.

I'm going to start by capping off the A/C and IMRC at the intake plenum and replacing the EGR (does anyone else thing exhaust gas recirculation is stupid?) and that should narrow it down.

I'm wondering... I don't know what to call it but the oppposite of the PCV valve, the other valve cover that has a line going to the air intake... does that need some kind of sealant? It seems to be connected into the grommet on the front valve cover well but what about where it goes into the flex hose to the throttle? Seems like an iffy connection there.

God I hate cars. I really would like this windhole if I could get it to pass.

Hi
I don't think the PCV "intake air" if you will has to be "religiously" sealed. I think it pulls from the intake simply to insure cleaner air into the PCV system.

As to your EGR - you can do a simple test. Place an ordinary straw over the vacuum port on top of the valve. Using your mouth you can pull a bit of vacuum and then release it. You should hear the valve clunk open and closed. If it does, it is likely operating o.k. . I will tell you from recent experience - yesterday, that the system is sensitive to a stuck EGR. At least one which is stuck open. I had tested the EGR with my vacuum pump and it obviously (in retrospect) stuck open. The car of course idled very poorly and I was a bit stumped. However, even on that short 2-3 min. run, the PCM sensed excessive EGR flow and lit up the CEL. After scanning the light I unstuck the EGR and all was well. I have also had the CEL for insufficient EGR flow, and changed out the DPFE for that. Point being: the system seems very sensitive to EGR operation. I would be hesitant to replace the EGR on a hunch with no other corroborating evidence.

Good luck

Hi again
Just re-reading and thinking about your problem. I don't know how much things changed from '96 to '98 but....on my van there are two vacuum reservoirs: one for the A/C controls which you mention, and one on the right fender well, which you don't. Just wanted to point out that on my system, the "large" vacuum line is connected to both, the fender line via a "junction" stashed down within the protective ribbed plastic tubing. Actually that "main" line pulls vacuum for the A/C, IMRC's, EGR and the EVAP cannister so capping it will disable most users of your vacuum system - again assuming they plumbed it similarly in '98. You might be better off working through each of those individually, pulling off and capping their vacuum source one at a time to help isolate which part of the system is/may be causing your leak.

I apologize if I am re-hashing work you have already done and talked about.


Best of Luck

I put the 4mm gasket on and I think it still leaks, allthough not as much.

I sprayed some throttle body cleaner on the seam and I thought I noticed it rev up just a little but if it did it was very slight, but I definately saw some bubbles at the gasket. It takes a long time for the code and the SES light to come on.

I did break a bolt on the manifold installation, is one broken bolt enough to cause a leak?

I found another problem BTW, a bad PCV valve which I had only installed a few months ago. It's running better than it ever has.

Maybe I didn't get it clean enough? I could have eaten off it.

Maybe I didn't use enough sealant on the gaskets inbetween the intake banks?

Maybe I knocked the gaskets out of line when installing?

Since it's only been on a couple of weeks would it be OK to remove the manifold and reinstall the same gasket?

I'm thinking about using a thin coat of sensor safe sealant to hold the gaskets in place and making sure I have a good thick bead on the inbetween parts.

Can I use 1/4-28 x 2-1/2" bolts from the hardware store or do I need to buy them from the dealer? I'm very fearfull of breaking them now, the torque for them is at the low end of my wrench and it doesn't work that well at the low end.

I've got a good understanding of how this stuff works but I don't have a lot of experience so I never know if I'm actually doing it correctly, so any tips are appreciated.

I've always wondered why you should not put some sort of sealant/ gasket dressing in situations where it states the gasket needs to be installed dry. I've used a product called Hylomar HPF (or Universal Blue) for years on my motorcycles and cars and never had a problem. Granted, this stuff isn't supposed to be gooped on, but when used properly- it's great.

Yes, 1 broken bolt is enough to cause a leak.....I know from experience.
If it is in the lower manifold, like mine was, you will most likely need to remove the lower manifold to get at it.....hopefully yours will turn out easily like mine did.
I took mine to a shop, just in case it did not turn out easily....
Also.....to be safe, I would put new lower intake manifold gaskes in...as they are not reusable. I would think that the end seals....that go onto the block between the heads....are reusable at this point.

I just got back from the dealership parts store, I ordered the lower intake gaskets and seals, all the bolts for the upper and lower intakes and a new A/C blend door switch for the dashboard, for about $140.

Judging from where the bolt broke, it should be just sticking out once I get the lower manifold off.

I found it interesting that the price for the gaskets and seals were competative with the aftermarket ones from Autozone or Advanced. $40 compared to $52 for the whole set at AZ, which just adds the six upper, throttle and IAC gaskets. Another item of interest is that one gasket costs $0.25 more than the other. I figured they were mirror images of each other, I guess not.

They had the gaskets in stock but not the bolts or switch, they may be in tomorrow. I hope so since I have a three day weekend to waste. Anyway, I'll update y'all when it's done.

Can someone please tell me, which way is front, right and left on the engine?

The gaskest block one of the coolant ports on each side, is this normal? It blocks it where it says "Right" and "Left" on the gaskets, actually.

Are these knock-outs to be removed prior to installation?

Can someone please tell me, which way is front, right and left on the engine?

The gaskest block one of the coolant ports on each side, is this normal? It blocks it where it says "Right" and "Left" on the gaskets, actually.

Are these knock-outs to be removed prior to installation?


Hi

I believe you will find the left to be the front bank and right on the rear. When I did them on my '96, it did not seem to me that I could reverse them as the alignment pins would not have gone in. I too noticed that there was "blockage" of a water port, but my originals had the same thing. So, no don't pop anything out.

From Wiswind's site:http://rides.webshots.com/photo/2406703960011220610bjzjxv

Hi

I believe you will find the left to be the front bank and right on the rear. When I did them on my '96, it did not seem to me that I could reverse them as the alignment pins would not have gone in. I too noticed that there was "blockage" of a water port, but my originals had the same thing. So, no don't pop anything out.

From Wiswind's site:http://rides.webshots.com/photo/2406703960011220610bjzjxv

I'm at work and webshots is filtered. I guess I got the left and right correct. The tabs fit and everything else lined up fine.

The reason I ask is because after I got it all back together, changed the oil and started it up it made a horrible clicking noise. It did that last time I changed the gaskets until the oil and water started circulating (at least I think that's what caused it).

The last gasket I had on there was after-market and the one port that was blocked was only partially blocked.

The OEM gasket was completely blocked, that makes no sense to me. I think the port closest to the thermostat was the one that was blocked and it seems this would prevent the coolant from circulating and the sound of the valves is echoing in the manifold. Like the difference between tapping on a full can of beer and an empty one.

It ran fine with the old gasket partially blocked, I'm thinking about cutting that piece out to see if that quites her down.

:disappoin

I would also advise NOT to cut any part out of the gasket.
I show pictures of the gaskets placed on the head, befor placing the lower intake manifold....and you will see how they look.
The locator pins are shown in my pictures also...and that is all you will need to keep them in place.

Again, FORD is very clear about dry fitting the gaskets.....so I would follow their advice....or you are more likely to have problems.

As mentioned.....Left side is the front of the engine...
Right side is the back of the engine.
Way to remember......it is a carry over from rear wheel drive days......
In rear wheel drive configuration......the transaxle would be on the rear, and the water pump, power steering.....etc would be on the front.
So when you turn the engine (in your mind), that is how left and right would line up.
However.....when reading about the history of the FORD 3.8L engine.....I clearly remember that they stated that there are some casting differences between the rear wheel drive version and front wheel drive versions of the engine......so parts may not cross over.

Uggg... :banghead:

I must have right and left mixed up. So if it was a RWD left on the engine would be my left if I was sitting in the car, not as if I was installing a gasket from the front of the car. My fault for thinking Ford would do things logically. :screwy:

I'm not sure now but I seem to remember thinking, looking at the engine standing on the passenger side, this is my left, this is right.

Those gaskets were also labled "front", I assumed that was the side with the belt, who knows...

That blocked coolant port would be furthest from the upper radiator hose if I switch them, allowing the coolant to flow through. That makes more sense I guess.

God, I hate cars.

I looked at the picture at home and it looks like the way I remember installing them.

I guess I have a new problem.