So my neighbors car is losing antifreeze. Abour a resevoir full in 2 days. Ive checked hoses seals water pump radiator heater core. Exhaust doesnt smell aweet. Heater is warm but not blazing hot. Its an 04 bonneville 3800 any ideas on what to do? Help guys he cant find the leak and I cant either.
pontiac bonneville mysterious coolant loss
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Which Series 3800 is it. If its a Series II 3800 it's the intake manifold (black peice on top of engine). You won't see it because it leaks in the inside. If its the 3800 series III with the metal intake manifold, I have no idea what it could be.
Yea its the gen 2 with the plastic intake. It leaks inside and goes where?
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Originally Posted By: chevyboy14
Yea its the gen 2 with the plastic intake. It leaks inside and goes where?
One of two places:
1. Into the intake runner, where it gets burned.
2. Into the valley, where it goes down and mixes with the oil.
Yea its the gen 2 with the plastic intake. It leaks inside and goes where?
One of two places:
1. Into the intake runner, where it gets burned.
2. Into the valley, where it goes down and mixes with the oil.
Theres 2 plastic elbo's between the engine and the tensioner bracket and the elbo's tend to crack and leak.
Ive looked all over the engine and its dry there is a kittke dampness on the driver side head area. At the very back of the head. The oil is clean as well.
it could also be as simple as a radiator cap
Wouldnt the radiator cap leak then
Originally Posted By: chevyboy14
Yea its the gen 2 with the plastic intake. It leaks inside and goes where?
Out the tailpipe.
Yea its the gen 2 with the plastic intake. It leaks inside and goes where?
Out the tailpipe.
Tell him to not crank the engine again until repaired or he could hydrolock the engine and destroy it with one revolution. It needs an intake and upper and lower gaskets. Change the EGR pipe to the smaller tube size replacement or it will burn the new manifold. Jesse, ASE Master Tech
Antifreeze in the oil doesn't take long to do damage.
I'd take Jesse's suggestion, and I think this is a common repair for those engines.
I'd take Jesse's suggestion, and I think this is a common repair for those engines.
It's a head-scratcher. No coolant in the oil, no white smoke, no visible leaks. If the overflow bottle is dry and the heater is only warm, the radiator is also low. If your friend wants to save the car, have a mechanic do a pressure test on the system. The '04 engine did not have the defective gaskets that plagued the '97-'03 engines. It could be the gaskets; but you would have noticeable signs.
We are doing a pressure test today but how can i be sure ita the intake gasket?
The gaskets go bad and the will usually leak on the outside but not bad and you won't loose a coolant tank worth of antifreeze in two days. The intake manifold itself degrades in the inside around the EGR valve inlet and lets coolant leak into the inside of the engine (the two holes to the right is the coolant passage to the throttle body). It can hold a lot more coolant in the manifold area than the pic suggest.
That's just when my upper intake gasket was leaking because the intake manifold warped. It would be much more if the EGR valve burned a hole in the coolant passages runnig thru it. BTW how many miles on the engine.
That's just when my upper intake gasket was leaking because the intake manifold warped. It would be much more if the EGR valve burned a hole in the coolant passages runnig thru it. BTW how many miles on the engine.
That much in 2 days should be easy to spot. The lower gaskets are the same make up as the 3.1/3.4 I have done alot of those. For external leaks on the 3.8 you have to look very carefully in the middle of the intake. Also make sure to really check the plastic elbow on the passenger side of the motor going into the lower manifold. They Leak all the time and Alot!!!!!!! If its slightly wet in that area you are going to them replaced.
John
John
Now i see why people are always avoiding the late 1990s and early 2000s (before 2004) GMs.
These are easy fixes? And was the 3800 Series III immune? 2003 was last year of issues? Again, "easy" fixes?
These are easy fixes? And was the 3800 Series III immune? 2003 was last year of issues? Again, "easy" fixes?
The problem with the plastic gaskets was solved during 2003. Maybe some late 2003 had the better gaskets but all of the 2004 model year did. GM did have some kind of recall if they failed early on; something like the first 20-30,000 miles and it was a sliding scale after that. So if your car had more than 50,000 miles or four years old, the reimbursement was around $50-100.
I wouldn't say replacing the upper and lower gaskets are easy fixes, but it depends on your ability. Like anything else the first one will take a weekend and I've heard some people can do it in a couple of hours. A GM dealer charges $750 for a 3.4 in a 2002 Grand Am. A 3.4 is a little more involved as you have to remove the push rods and in the 3.8 they are not in the way.
I wouldn't say replacing the upper and lower gaskets are easy fixes, but it depends on your ability. Like anything else the first one will take a weekend and I've heard some people can do it in a couple of hours. A GM dealer charges $750 for a 3.4 in a 2002 Grand Am. A 3.4 is a little more involved as you have to remove the push rods and in the 3.8 they are not in the way.
Originally Posted By: PhillyJoe
The problem with the plastic gaskets was solved during 2003. Maybe some late 2003 had the better gaskets but all of the 2004 model year did. GM did have some kind of recall if they failed early on; something like the first 20-30,000 miles and it was a sliding scale after that. So if your car had more than 50,000 miles or four years old, the reimbursement was around $50-100.
I wouldn't say replacing the upper and lower gaskets are easy fixes, but it depends on your ability. Like anything else the first one will take a weekend and I've heard some people can do it in a couple of hours. A GM dealer charges $750 for a 3.4 in a 2002 Grand Am. A 3.4 is a little more involved as you have to remove the push rods and in the 3.8 they are not in the way.
Yes it can be done in a few hrs(gasket prep can add a bunch of time). I wish every lower intake manifold was this easy. I feel its harder to remove the alt and belt tensioner on the 3.8 than the manifold its self. On the 3.4, if you have the proper tool you do not even have to remove the ALT, Coils and rear valve cover. They take me about 2.6 hrs or so to do.
The problem with the plastic gaskets was solved during 2003. Maybe some late 2003 had the better gaskets but all of the 2004 model year did. GM did have some kind of recall if they failed early on; something like the first 20-30,000 miles and it was a sliding scale after that. So if your car had more than 50,000 miles or four years old, the reimbursement was around $50-100.
I wouldn't say replacing the upper and lower gaskets are easy fixes, but it depends on your ability. Like anything else the first one will take a weekend and I've heard some people can do it in a couple of hours. A GM dealer charges $750 for a 3.4 in a 2002 Grand Am. A 3.4 is a little more involved as you have to remove the push rods and in the 3.8 they are not in the way.
Yes it can be done in a few hrs(gasket prep can add a bunch of time). I wish every lower intake manifold was this easy. I feel its harder to remove the alt and belt tensioner on the 3.8 than the manifold its self. On the 3.4, if you have the proper tool you do not even have to remove the ALT, Coils and rear valve cover. They take me about 2.6 hrs or so to do.
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