Thread: LIM shange or head gaskets??????

Hello All,What I have:I have a 98 GTP with no mods that I am aware of. It has 215,500 miles. I've had the car for about a year and a half. I bought it Memorial day of 2017. I've put about 7,000 miles since I've had it. I've had a coolant leak the entire time I owned it. I've gotten warning lights that the coolant is low. I have filled the coolant not fixed the coolant leak. It still has the plastic elbow from the lower intake to the alt bracket. There doesn't appear to be a elbow on the lower end of the bracket. Since I've owned it, it has never shown signs of overheating from what I can tell. The temp has never gone above 215 degs. What happened: I was out on a Sunday when a Ford truck pulled up beside me. There was construction ahead that reduced the traffic down to 1 lane. HE made a move to get a ahead of me and I floored the gas and got ahead of him but I stuck behind at a traffic light. While sitting at the traffic light a saw steam coming out from under the left rear tire and up around the gas cap filler. I drove it another 1/4 mile where I parked it. I looked under the hood and could see coolant shot out from an unknown location. I went inside to get something to eat while it cooled down. I came around the car to a trail of coolant following me around the parking lot. I came outside to the large puddle of coolant under the car. I drove it home via the interstate keeping the speed at or below the speed limit (65) and the rpms as low as possible. I parked it in my yard for later diagnosis. I filled the radiator with straight water since I knew it wouldn't stay in it for long. one of the heater hoses blew when I got on the gas. I ordered new hoses and replaced them the next day. Replaced the hoses and filled it with water to see what else might be wrong. Started the car and tried to bleed the cooling system. . I got a lot of air out of it while it was running and when it was shut off it spewed water from the radiator like Old Faithful. The oil still is "clean" and not contaminated by water. The water showed signed of having black residue in it. I am still trying to figure out what might all is wrong with it. Do you guys think it might be the head gasket(s) or just a LIM issue with the supercharger pumping air into the cooling system? Any advise would be helpful.James

Scotty,

I got a lot of bubbles from the radiator while I was checking it. That's why I was wondering if the heds gaskets were bad or if the supercharger was pumping air into the cooling system.

That is an option too but I do think I need to address the plastic elbow issue. I've been watching videos on YouTube that deal with head gasket diagnostics, LIM diagnostics, and plastic elbow replacements. While enlightening, they are also not helping the diagnosis.

I have the tools, Chilton manual, and patience to do a LIM/elbow change over a weekend. If all went well and I don't see bubbles in the radiator as before then I could call it good.

Bill,
It was a total of about 5.6 miles of on and off throttle to keep the rpms low.
The alt bracket has the metal elbow going into the timing cover. I checked the heater hose connections after I filled it with water. I didn’t notice any leaking.
Thanks for the suggestions

Rent or buy the combustion gas tester from AutoZone. If it's the supercharger, it'll stay blue, if it goes yellow, headgasket.

If it's not bubbling still, rent a pressure tester, grab some uv coolant dye and a blacklight and your leak will light up like a Christmas tree in about 30 seconds after you've cycled the dye and pressurized.

As far as mystery leaks go, I tried the above and it actually ended up being my overflow tank had a very small crack that seeped coolant when it was a certain level. Never would have found it without the dye.

Good luck!

I stopped by the local O’reily parts store to check out a combustion gas detector. It was like I was talking a foreign language. That got me nowhere. I seriously don’t think they are qualified to sell auto parts. I ordered the plenum gasket set and they have the lim set in stock. I bought spark plugs and wires last year but never got around to installing them. I also am going to check compression if I can get to all 6 cylinders.

I'm not terribly surprised, but really tough, don't waste your time or money trying to throw parts at it. Trust me, I've been there.

The full gasket set from rockauto is cheaper than just the lower at the parts store.

Here's the link on AutoZone site: Best Loaner Block Tester Parts for Cars, Trucks & SUVs

And here's Amazon for $37: Amazon.com: Block Tester BT-500 Combustion Leak Test Kit - Made in USA: Automotive

I have the lim gasket set, plenum gasket set, elbows. Tomorrow we start the tear down and re-assembly to “fix” the problem. We will see where that gets us.

@jamesc43 Good luck! Hopefully this is the issue after all, but if it isn't just let us know! Oh, and if you were interested, Lisle no spill funnel is by far the best thing I have ever used for bleeding the cooling system on these cars.

Gentlemen,

I took the engine apart, cleaned the parts, the LIM intake gaskets were the new metal style from Felpro. I replaced the LIM gaskets, installed the metal upper elbow. I replaced the spark plugs,
wires, and coolant. I started the car and bled the cooling system several times. Each time I got less and less air out of it. I found the metal elbow was leaking coolant. I removed the alt bracket.
I replaced metal elbow and cleaned the gasket surfaces again. I reassembled the car again. I bled the cooling system and found no leaks this time. So far I have not had any leaks and no air
from the radiator. So far so good.

1 have a secondary problem now.

I live in Colorado and own a 01 Subaru Outback Wagon with 205,000 miles. It has been my daily driver for the past 14 years. It is due for some serious routine maintenance coming up. I have been
in the market for a newer, more efficient car to replace the Subaru.

I also have the 98 GP GTP. It has been my secondary auto. I enjoy the power after driving the gutless Subaru. The engine issue was a possible deal breaker and I wasn't sure I was going to be able
to fix it in my backyard. If I couldn't fix it I was going to get rid of it.

With the above in mind a found a 05 GP GTP Competition Group with a price and mileage (120020) that I couldn't pass up. Links to pictures are below. Now I have 3 functional cars but I only can justify 2 to myself.

Which should I keep and which should I retire to another person?

http://<center> <a href="http://s125...</a> </center>

Lets try those links again.

2005 Pontiac Grand Prix GTP Comp G Edition Photo by jamesc43fly | Photobucket

One of my coworkers suggested I get rid of both the Subaru and the 98 GP and just keep the 05 GP. The Subaru is great for driving in Colorado but I didn’t have it before 2004 so I think I can live without it.