Coolent leak on a '97 Pontiac Bonneville SSE?

Question

'97 Pontiac Bonneville SSE with just a hair over 100,000 miles that has a small (few drips underneath the car when she sits for awhile) coolent leak from passenger side of the car, just north of the passenger side tire. I do notice some moisture on the front on the water pump, but it is minimal. I just had the upper intake manifold and the coolent bypass elbow repalced (very typical coolent problems for this car) and the hoses are all less then 3 years old and they all seem to be (visually) okay. Bought car in '04 with a little over 60,000 miles on her and I havent replaced the water pump while I've owned it so I believe that may be the problem. Any way to know for sure? Any other things to check before I buy a pump? Any special tools required to do such a job yourself? I have done work on cars before ( brakes, timing gear and chain replacements, etc..) So I know basic repair how-to, just don't want to get in over my head with this one. Thanks!

Answer 1

You already know about that crazy plastic elbow with orange o rings and how the tensioners hook around the alternator and front cyl head. Water pump started to leak once you got new coolant into the engine and all the other leaks stopped up. Just the normal mechanic tools and skinned knuckles 3.8 liter is almost easy good luck.Take your time catch the coolant allow 4 hours don't break off that elbow into the manifold several bolts in the alternator bracket are kind of hidden buy a good drop light.

Answer 2

It could be the water pump, but first check the black plastic elbow that goes between the intake and the water manifold (the part above the pump). When the intake was off they should have replaced this (but probably didn't). These always go bad on the 3.8's. There are also O-rings where the heater hoses connect on the back passenger side of the engine that can leak, but less likely the cause. These are both cheap (less than $20) fixes and easy DIY. Best way to check is to hose off the coolant and then warm up and check these areas. If it's the water pump it will be leaking behind the pully (they leak out a weep hole in front when the bearings go bad). Since yours is not supercharged the water pump is pretty easy as well, and run around 60 for the part. I would also check/replace any worn idler wheels for the serpentine belt, very common failure on that milage 3.8 as well.

Answer 3

Could still be that bypass hose (goes from the tensioner into the lower intake manifold). I've read online you can find metal elbows to go in there, though I don't know how reliable that information is, I'll find out soon enough. My wife's tensioner just went out in her 97 Bonneville, and the elbow broke off at each end after the o-rings, so I'll be on a quest to replace that elbow tomorrow :)

Unless that moisture is from a weep hole on the water pump, I wouldn't guess your water pump would be the issue.

part number is...24503423 coming from that source...seems true.... gmpartsdirect.com pulled a part from that number that's consistent with the description. (less than $10)

Answer 4

Can of worms here.The best way to start is get athe cooling system pressure tested first. This is cheap and any good shop can do it in 5 min.This is the best way to see where te leak is. If it is comming from around the water pump it is a pretty easy fix that you can do your self at home. Have done countless #s of these. Good luck.

Answer 5

it sounds like the pump and you can do that one at home. get a good light and inspect everything for other possible leaks.but if you see moisture on the pump it is leaking.