So I got a deal that was too good to be true

[Kyle]

Possibly anyways. I bought a 2000 Pontiac Grand Prix GTP today for $1500. Its a little high on mileage at 154k, but runs and drives great.

SEL is on for low efficiency bank 1 catalyst system. So my thought, ok no big deal the cat is probably bad and the car still drives great. It's not the first time I've seen a bad cat on one of these. I take it for a test drive and the temp is solid and the heat is blasting hot!

Fast forward to 30 minutes ago. I get in it to move it around in the driveway so its no blocked in. As soon as I start it, I hear that rushing water sound inside the dash. Go look and the overflow is pretty low. No big deal I hope, right? I went to Wally world and picked up some dex. Come home and pour it in, there is leak in the line from the tank to the radiator. Not a big deal, right? Pop the cap off the radiator and the damn thing appears to be just about empty!!!!!!!

Weird thing is, it wasn't over heating on the test drive. I put the dex in and the temp is up and down at a stop leak air is trapped in there. I don't know how much dex is in there since I only bought a gallon, but figured I'd take it for a spin real quick. Still no overheating as long as its moving, the temp stays about a 1/4 way up the gauge.

In short (lol), I may have gotten screwed. I'm hoping that all is well though. I'm gonna get a new radiator cap tomorrow and replace the leaky hose. Hopefully after topping off the system and bleeding the air out all will be well in GTP land.

If not, think there is any chance of getting my money back on it? lol

[71chevellejohn]

Depending on the engine(3.8 V6 I'm guessing), it may have a leaking upper intake manifold gasket. My brother is the mechanic, so I'm not 100% sure, but if I remember right it will almost act like a blown head gasket(low coolant, overheating, etc). I think the book calls for 3-4 hours but it can be done quicker. If you pull the upper intake you'll see coolant in the plenum area.

Like I said, I don't know for sure but it's the first thing that comes to mind on those 3.8's.


EDIT - just re-read and saw it is a GTP, is it a SC engine?

[JC316]

Depending on the engine(3.8 V6 I'm guessing), it may have a leaking upper intake manifold gasket. My brother is the mechanic, so I'm not 100% sure, but if I remember right it will almost act like a blown head gasket(low coolant, overheating, etc). I think the book calls for 3-4 hours but it can be done quicker. If you pull the upper intake you'll see coolant in the plenum area.

Like I said, I don't know for sure but it's the first thing that comes to mind on those 3.8's.


EDIT - just re-read and saw it is a GTP, is it a SC engine?

The GTP is the supercharged 3.8L. Yes, they are notorious for blowing the intake gasket thanks to that fucking orange shit that GM called antifreeze and the craptacular gaskets they used. With this hard freeze, I would be far more concerned with a cracked block than anything else. Check the oil, see if the level has increased or if it's milky.

[Kyle]

The GTP is the supercharged 3.8L. Yes, they are notorious for blowing the intake gasket thanks to that fucking orange shit that GM called antifreeze and the craptacular gaskets they used. With this hard freeze, I would be far more concerned with a cracked block than anything else. Check the oil, see if the level has increased or if it's milky.

It is a supercharged motor. No the oil doesn't show any signs of having a blown head gasket. That was the very first thing I checked when I was there. I hoping that its just low on water from having a leak in that hose. Doesn't make sense why the coolant would be low in the radiator, but I guess we will see.

[JimD]

3.6 hr book rate on the intake gasket change( Alldata)

[butt86]

If not, think there is any chance of getting my money back on it? lol

maybe depending on how much money you want back out of it i may be interested...

[butt86]

It is a supercharged motor. No the oil doesn't show any signs of having a blown head gasket. That was the very first thing I checked when I was there. I hoping that its just low on water from having a leak in that hose. Doesn't make sense why the coolant would be low in the radiator, but I guess we will see.

also check the coolant elbows, those are notorious for leaking...

[tkblkcobra]

From consumer guide...

Coolant leak: Coolant loss via plastic intake manifold is corrected by installing upgraded manifold and gaskets plus new PCV kit. (1997-03)


Coolant leak: The 3.8-liter V6 may leak coolant into the engine from the intake manifold. A new gasket kit, revised throttle body nuts, and sealing compound is available. Redesigned manifolds are also available in the aftermarket. (1997-2004)

[turbos66coupe]

coolant elbows that are near the water pump, they are plastic and leak all the time. you can get them at AZ in the help section. also intake gaskets are notorius on those motors, 3.1,3.4, and 3.8's if they are leaking it will be easy to see just check the corners of the intake. if they are use felpros redesigned kit its more expensive but does a little better.

[tkblkcobra]

I'm not sure if the supercharged engine has the same intake. Here is a replacement from Dorman. You may want to have a dealer run the vin to see if the recall was run on a oil leak from the valve covers. There were a bunch of these cars that burnt to the ground. Plastic wire retainers that caught on fire from oil dripping on exhaust manifolds.

3800 Series II Intake Manifold
Item # 3000002

$119.99
Fits: 3800 Series II (VIN K)
Position: Upper
Dorman PN: 615-180

Replaces OEM #s
89017272
89017554

LIFETIME WARRANTY


Brand New High-Quality Dorman OE-Solutions Replacement Upper Intake Manifold
This redesigned intake features:
Increased EGR wall thickness to eliminate corrosion
Reinforced structure to withstand an engine backfire
New plastic & silicone gasket already installed (a $35 value)

Dorman's OE-Solutions all-new intake has been redesigned to eliminate the weak areas that cause the OEM intakes to fail. The OEM manifolds fail due to extremely hot gases from the EGR tube which corrode the plastic area around the coolant passage. This causes a coolant leak into the engine and symptoms similar to that of a bad head gasket. Our new intake has a thicker EGR wall and a new EGR tube that will create a cooling pocket between the intake and tube.

[shumpertdavid]

If you have access to a cooling system pressure tester, you'll be able to make quick work of finding leaks. Fix the leaks you know and pressure the system up and look for any other possibly leaks. Best part about the pressure tester is that you don't have to get the motor hot since you don't have to run the engine to produce it's own pressure as the system heats up. Some leaks will only be present at certain pressures. I've been able to find leaks easier this way. Just my 2 cents.

[butt86]

I'm not sure if the supercharged engine has the same intake. Here is a replacement from Dorman. You may want to have a dealer run the vin to see if the recall was run on a oil leak from the valve covers. There were a bunch of these cars that burnt to the ground. Plastic wire retainers that caught on fire from oil dripping on exhaust manifolds.

between the oil drips and the plastic fuel lanes randomly breaking its a wonder these cars didnt all burn to the ground....

[JC316]

It is a supercharged motor. No the oil doesn't show any signs of having a blown head gasket. That was the very first thing I checked when I was there. I hoping that its just low on water from having a leak in that hose. Doesn't make sense why the coolant would be low in the radiator, but I guess we will see.

If the oil isn't milky, then it isn't an intake gasket, it directly mimics a head gasket. You could be right, it may just be low on coolant.

[Kyle]

If the oil isn't milky, then it isn't an intake gasket, it directly mimics a head gasket. You could be right, it may just be low on coolant.

When it was all said and done, the car took about a gallon and half of coolant!! I replaced the radiator cap while I was filling just to be safe. Temp was rock solid at 210* while driving and letting it idle for almost 30 minutes so for now I think I'm good. I did however smell some burning oil while idling excessively. The recall thing isn't a bad idea. I'll try to check that out tomorrow.

[32vfromhell]

210 sounds awfully hot for 20 degree ambient temps....

imagine what it would be in the summer.