I finally found out why my car was overheating. There is a small leak in the front drivers side intake manifold flange where it bolts to the head. There was a small amount of coolant along the manifold which i assumed was coming from the thermostat housing. I rinsed the area off and then started the engine, the left over water was bubbling when i turned the car off. This was happening only in the area where the water puddled and was not from the heat of the manifold. Ok that said here are my questions: Is this common for the 5.7 TPI manifold? Is there an easy fix that someone has come across, or do i remove the TPI unit and manifold, then reseal?
Any help or comment would be appreciated.
Thanks in advance, eric

 

'92,

Welcome Aboard!

I've been on and off the board for a couple of days now, and I've had and seen a few TPIs. It doesn't appear to be a common point of failure, or at least no more than any other engine.

The best solution would probably be to remove and reseal the intake. It is possible, though unlikely, that soem of the bolts elongated or worked loose. You could re-torque the intake bolts with the engine hot just for grins, but I have my doubts about that working.

 

Thanks for the response. I am glad that I am not getting a lot of responses about this being common to this intake manifold. Time for a tear down.

 

My formula was leaking from all 4 corners of the intake gaskets, but it had 170k on it at the time... so they had pretty much lasted as long as could expected. =)

It wasn't a very difficult job to do, although the whole TPI looks a bit intimidating when you've never torn down a MPI intake before! Keep good track of where all those damn vacuum lines go, and you'll be much happier...

 

'92,

Plan ahead before you tear into it. The board message archives are an excellent resource if you take a little time to search for your topic.

You'll need to acquire a gasket set (FelPro 93035-1 or equivalent), a small jar of anti-seize compound, a good quality T-40 Torx driver bit (don't cheap out on this or you'll be posting back with something like "Help! Stripped Torx bolt on intake!"). You'll also need penetrating oil, like Wd40 or CRC 5-56, a 3/8" drive torque wrench, a digital voltmeter, some sensor-safe RTV silicone gasket sealant, antifreeze concentrate, shop towels, something to make identification labels for wire connectors and vacuum lines, a good gasket scraper, some common hand tools, and about a day and a half of your time to do it correctly.

If you've ever planned to port the intake plenum, this would be an excellent time to do so. You can research what is involved in this download - Plenum Porting.pdf and decide for yourself.

It would also be an excellent time to send the injectors off for cleaning and flow-matching. If the engine has more than 75,000 miles or so, or if you've ever had suspicions about your injectors, you might want to check out the services at Cruzin' Performance - they are fast and inexpensive considering the excellent service, or about $10 per injector or less if all they need is cleaning.

And since you'll be exposing the camshaft, you'll get a good look at the conditions there. I don't expect you'll find anything wrong on a roller cam setup, but be thinking about it anyway - it's a good time to clean up the lifter valley and inspect the lifters at least.

The fuel rails and regulator will be exposed, and for a little more time you can convert the fuel pressure regulator to an adjustable type. Materials cost about a whole dollar, and the outline is detailed in this download: AFPR Conversion.pdf

You should also plan on cleaning the base of the EGR valve and EGR passages in the inkake manifold, just to prevent problems in the future. Just remember to avoid the use of any solvents on the EGR valve itself, since the internal pilot diaphragm can dissolve and be destroyed - use a small wire brush and scraper only. The mainfold can be cleaned with anything, so have at it.

Beyond that, the rest of the gasket swap is pretty straightforward - just like any other intake gasket set.

Good luck. We'll all be here for any questions.

 

Thanks for all of the info. guys. After reading your excellent posts and all of the links, I realized that I just don't have the time to do the repair myself . Daily driver and I work 55 hours a week. I will probably have it done by Arizona speed and marine, unfortunately I will have to have a new ported manifold installed, and that darn throttle body replaced, o yea larger tubes will be needed, especially with the larger cam I will have to have put in, maybe even new heads, don't want to leave old ones on there, might damage that new intake! (this is what I told my wife and she agrees ) shhhhhh, don't say anything . I will let you know the results.