3.1L coolant leak

[vicslic]

99 lumina 3.1L, 198,000 mi., LIM replaced by dealer at 50,000 mi. I know the lower intake manifold (LIM) is common problem, but I wonder if a steady drip from behind the top area of water pump housing, left side, can be a cause of leak, or is it always the LIM. Can't see behind there to see if it is LIM or ?? Plan to replace LIM, but wondering if anyone has ever had water pump housing leaking between back of housing and engine block??.

[Airjer_]

timing cover is also a common leak. Although they typically happen at a much higher mileage than the LIM.

[vicslic]

Thanks, Airjer. You've confirmed my suspicion. Got a better look and did not see LIM leak, just very small weep on driver side. However constant drip behind time cover gasket, and at 198,000 miles it figures well with you experience. will not replace LIM, but will go after housing gasket first. I just was not sure if the water route ran all the way from the water pump to the left and half way down the timing cover. Haynes does not show a clear route for water circulation, but I think I see it now. Thanks again for your help.

[jeffcoslacker]

Originally Posted by vicslic

Thanks, Airjer. You've confirmed my suspicion. Got a better look and did not see LIM leak, just very small weep on driver side. However constant drip behind time cover gasket, and at 198,000 miles it figures well with you experience. will not replace LIM, but will go after housing gasket first. I just was not sure if the water route ran all the way from the water pump to the left and half way down the timing cover. Haynes does not show a clear route for water circulation, but I think I see it now. Thanks again for your help.

At that mileage, I'd put a timing chain set in it anyway while it's apart. It no doubt needs it...they typically go bad around 175,000...you're on borrowed time...

[vicslic]

You are correct, Jeff. The timing belt is very slack on left side and taught on the right. Will change that too.
One thing strange I noticed while removing one bolt near left mid timing cover, coolant came pouring out of the bolt hole like a water spout. Is that usual for the bolt to go through into the coolant?? Never seen that. thanks all, this really helps.