Intake manifold leak

wassup? I am having coolant leaking from underneath the intake. I did some research and concluded that I have to change the gasket. My question is, what is the complexity of changing the intake manifold gasket? thanks

tahoeman for ever!!!:cool2:

Are you talking air intake manifold?:skep:

You don't say what year or engine, so no specific answers for you. Whatever you have, you need to get some instructions, Chilton's or Haynes manual, or a service manual on DVD or something like that. The job is not rocket science, but there are some things that should be done in sequence and some pitfalls to avoid by knowning the proper procedures.

Good luck.

Fore example when reinstalling the manifold if you don't torque it in the proper sequence you will warp it.

Whats up tahoeman dude i'm having the same problem now with my 99 tahoe i knew it was leaking but soon as the cold weather hit it must of contracted and now its leaking like my ac drips its bad. i'm going to check mine out within a day or two let me know what you come up with. is your leak coming from the back of the motor?

Are you sure it's your manifold gasket? There's a coolant hose that connects to the manifold close to the throttle body on the passenger's side. Water seeping from this will drip from the engine and make you think it's coming from the gasket. Check it out before you tear into it.

The 5.7 Vortec engine is notorious for the intake manifold leaking coolant. I had a 97 Chevy pickup with this engine, and it leaked coolant badly. At the suggestion of a mechanic friend of mine, I removed a few of the intake manifold bolts, coated them with RTV, and re-installed them. If I remember correctly, it was the front two on both sides. This worked for a while, but it started leaking again after about 6 months. So far, my 97 Tahoe hasn't had this problem (knock on wood).

I hope this isn't a problem with the 07 on up, well I guess that is why I have the 100,000 mile warranty.

wassup guys? thanks for the replys.... btw, i have a 5.7 vortec, 2wd... it seems that it leaks from underneath the air intake manifold, the leak comes from the front of the motor. it leaks when it is park on my hill driveway.... the tahoe does not overheat though when i am driving it.... i am constantly adding coolant to the resouvier compartment,, but the radiator is full.... weird. i must fix this leak until it gets worse. I hope as well the new tahoes don't have this flaw as well, because i love them so much!

My understanding (non-GM-Technician here..) is that the intake manifold gaskets were each made of 2 materials, a plastic and a metallic. The issue was that they would either seperate, or not expand at the same rate, and it would leak typically as the engine was cold.. as the engine heated up, enough swelling occured to seal off this leak.

Again just my understanding of it as told to me by a few various yukon/tahoe owners... it is not the same block as the new ones.. this problem should be confined to 96-99s.. possibly it was even fixed in 98 or 99.

i found on quite a few i had was just snugging down the 8 intake bolts cured the leak.

2000 tahoe, rough idle, P0171 & p0174, engine stumble when cold

This is my first post, but I thought I'd let you know the successful resolution to my problem since I found your forum helpful in my trouble shooting. I hope this might help others.

2000 Tahoe, 5.3L, 4wd, 103,000 mi.

Symptoms:2000 tahoe, rough idle, P0171 & P0174, engine stumbles off idle when cold.

Essential Tool: Auterra Dyna-Scan OBDII software on Palm 71. Used this for determining stored codes, resetting codes, monitoring O2 sensor voltage (graphed in realtime), monitored short and long fuel trim (very helpful, especially long term which was at +25% continually when I began troubleshooting, indicating a lean condition), MAF, and others.

Procedure: Checked easiest to hardest:
Fuel Infectors: Used two bottles for Chevron Techron in two successive tanks of fuel. No change. Therefore injectors probably not clogged. (This stuff is good).
MAF: read .55 lbs/min at 600rpm (warm idle). Cleaned and rechecked. no change. OK
Vacuum connections: disconnected and plugged all vacuum lines sequentially to rule out problem with power brake booster, pvc valve, fuel pressure reg, MAP sensor, canister purge valve, and that is all the vacuum connections I could find. Cleaned PVC valve. All OK.
Checked intake runners individually with brake cleaner and then propane to check for intake gasket leak. Saw immediate richening on half of the intake runners. Knew I had found a leak. Snugged the 10 bolts, MAF went up to .62 lbs/min indicating an improvement, but still had rough idle and lean condition.
Decided to replace both upstream O2 sensors anyway since they've been working for 100,000 miles and they are easier than the intake gasket.
The O2 sensors cleared the lean condition (long term fuel trim began coming down, and p0171 and p0174 codes stopped coming back. The stumble off idle when cold ceased too.
Still have rough idle, but this condition will clear up with a new intake gasket I'm sure.

My conclusion and the interesting point this is even though the vacuum leak was present all the time, most of the symptoms were caused by sluggish O2 sensors even though they appeared to be doing their job when I monitored them on scan tool. They gave a nice waveform that appeared normal, but was actually askew. Two things needed to be fixed to clear all the symptoms.

Sometimes for the rough idling can be due to a faulty regulator.... This regulator happens to be inside the manifold... when this regulator fails, it can start leaking crude fuel into the intake, making your tahoe shaky.... this is what my mechanic told me... so you might consider taking a look at your regulator.

Actually I did that too. The fuel pressure regulator is on the driver side of the intake manifold just above the fuel rail. Pressure was 62lbs. with the vacuum hose removed and drops to 55lbs. with the vacuum applied. I believe this is normal. The symptom to look for with the fuel pressure regulator besides proper pressure is leaking fuel from the regulator when the vacuum line is removed.

my gasket broke around 150k. thankfully it didnt take out my engine when it went. but you do have to remove the lower part of the intake. you dont have to remove the upper part to remove the lower part. but you do have to drain the coolant and you will need to do an oil change. BUT that hardest thing you are going to run into is timing the truck again because you have to take out the distributer. to time it you have to have the GM Tech 2 scan tool. i was lucky and i guy at my work had one. but i think it would be less trouble if you had the chevy dealer time it for you. i think it would only be a few hours of labor. i dont know how much it is there but her in Denver it is $105.50 an hour!!!!!!!

Like stated above very common on these 5.7L. Don't be like me and do it the cheap way by using that Radiator stop leak crap. Sure it worked for a little while but my Radiator finally clogged up on Friday and now my engine is getting rebuilt
:mad2: The gaskets have been updated by GM to fix the problem.

sadly the parts have not been updated according to my chevy dealership. that was one thing i was so mad about.

Thats funny My GM tech told me they where updated. Come to think of it I can't believe I listened to anything a GM tech had to say:lol:
The Gasket I bought was #89017465

yeah im going to school to work on Toyota's and there is a GM class at the same time as mine and to me a lot of them seem to be questianable. not sure i would trust some of them to work on my truck.

i think that is the same part # of the one i put on my truck. from the looks of it the gasket looked like the one that broke on my truck.

i really do wish that the would have updated it. that way i wouldnt have to replace it in 150k again.

just go with Felpro gaskets instead.