98 Venture pass side coolant leak housing?

[Loonylani]

I have a 1998 Venture with approx 89000 miles on it. I have replaced the water pump once, water pump gasket twice, intake gaskets once and just did intake gaskets and head gaskets this week. When I started it was leaking at the intake gaskets again I thought. I got it all back together and water poured/trickled out the passenger side of the motor again. It it not the water pump or weep hole. Is it possible that the water pump housing is cracked? I cannot see any place for it to be leaking that hasn't just been replaced or resealed. I had a shop pressure check it and they were stumped. It seems to spray out by the water pump but not at the gasket.
Has anyone done a water pump housing replacement and what does it involve?

[roadrunner2]

Originally Posted by Loonylani

I have a 1998 Venture with approx 89000 miles on it. I have replaced the water pump once, water pump gasket twice, intake gaskets once and just did intake gaskets and head gaskets this week. When I started it was leaking at the intake gaskets again I thought. I got it all back together and water poured/trickled out the passenger side of the motor again. It it not the water pump or weep hole. Is it possible that the water pump housing is cracked? I cannot see any place for it to be leaking that hasn't just been replaced or resealed. I had a shop pressure check it and they were stumped. It seems to spray out by the water pump but not at the gasket.
Has anyone done a water pump housing replacement and what does it involve?

If you had to replace the intake manifold gaskets again, you must have been given the old style gaskets which were no good.

The revised gasket kit came out in Feb/2003.

The only sure-fire way I know of to locate a coolant leak (aside from an external one) is with a coolant pressure test.

[Loonylani]

I had a shop pressure test the system and it sprays out to the left of the water pump if you're looking at the side of the engine. It is not very clear where it is coming out. Hairline crack? Has anyone experienced this before?

[merc81]

The front cover of the engine has a water passage from one side to the other. There are a couple of bolts that go right through the passage and could be leaking. These are the larger bolt heads, one on either side (front & back as it sits sideways) of the front cover. You could remove these and recoat them with sealant to see if that's the problem--its likely you will have to remove the front cover and install a new gasket though. Not sure if this can be done without dropping the engine frame down--the harmonic balancer needs to come off first.

[Loonylani]

Thank you very much Merc. That is a big help. We were wondering where the coolant went through on that side. I had to drop all that and down and remove the balancer last year to replace the oil pump. Is the reason for dropping the motor so you can get a tool on the balancer? or is there a way around loosening the subframe and all the mounts just to remove the balancer?
*sets fire to van*

[merc81]

" *sets fire to van* "

Really, its not that bad. I'm not sure you need to drop it, I just never tried it while the engine was installed. This would be a realy easy thing to deal with if it wasn't so close to the wheel well cover and the battery and all. I know you can remove the belt pulleys while the engine is in place. I know you can gain access to the balancer by unbuttoning the splash shields in the wheel well (careful, the abs sensor wire is clipped on to it). I'm just not sure if you have enough room to get all the stuff off that you would need to remove the front cover so you can change the gasket under it.

On the bright side, you may not need to change the gasket, the sealant on those bolts may do the trick.
If you are old enough to remember guys landing on the moon, then you perhaps have seen chevy engines with water pumps that bolted on the front of the engine on the left and right side, but had a gap behind them and the timing chain cover? The water passage was out the driver's side head, into the front mounted water pump, and out into the passenger side head.
This is that same engine style, but they have replaced the front cover (in this case the side cover) with a cast aluminum section that allows for the new water pump style, and all those idler pulleys for the belt and alternator and the mounting for the power steering, etc. Underneath all that is the old chevy block just like it looked in the 70s.

The two bolts you want to inspect and maybe reseal are the main ones that would be on the left and right side of that old style water pump that is no longer used. The bolt holes go right through the water passage on both sides.

John

[Loonylani]

Ok. We tore the side down and took off the harmonic balancer and such. It turns out it is the timing cover gasket that was leaking. We went ahead and replaced the chain and gear and put a new gasket on and it is not leaking anymore, anywhere (knock on wood). You should never say, 'there is no coolant leak' andwhere near a Venture. We didn't have to jack the motor up or do anything drastic to change the timing cover gasket for those of you out there who have this worry.
Thanks John.

[Adam M.]

Hello-I found this thread, and have some questions concerning a leak I have sprung in this general area of my Chevy Venture. I pressure tested the coolant system, and I can literally hear a hissing coming from a point where the timing cover and block meet. It's in the little runway where the power steering pressure hose lies when it's attached. (if you are looking at the haynes guide, page 2A-12, diagram 12.12a, its coming from right behind the left most arrow) Any ideas on how one might fix this? Do I need to remove the cover? Why is coolant leaking from the timing chain cover? HELP!!

[Adam M.]

merc81-You mentioned the two bolts with larger heads as the ones that may need a sealant. What would you recommend I use? I'm going to try it before I take of the timeing chain cover.

[merc81]

Originally Posted by Adam M.

merc81-You mentioned the two bolts with larger heads as the ones that may need a sealant. What would you recommend I use? I'm going to try it before I take of the timeing chain cover.

If you have only the one leak, then it would likly be the bolt that runs clear into the number one cylinder housing in the block. I think I have a photo...I'm sorry this is going to be a really big photo, I'm at home and can't edit the size of the pix from here, but look on the left side, just below the large water hole. That is the only bolt that penetrates the water jacket in the block and it needs sealed with permatex gasket sealer. This stuff comes in a 1/2 pint jar with a brush applicater in the lid. Its pretty standard stuff at the auto parts store.
I've included a couple photos below, and Monday I'll edit them down to a smaller size.
But, look at the second pix. On the circle pattern on the left side, the bolt to seal is the one at the 11 oclock position. Again, sorry for the huge photos, I'll fix 'em Monday.
I'd certainly start with that one bolt and see if it seals the system. I'm thinking that will do the trick for your leak.
If not, its not too hard to pull the whole cover off and re-seal it, just tedious.
John

[Adam M.]

Thanks a ton, merc-my leak is coming from the area where the stamped letters are in the 2nd photo. I can pressurize the coolant system, and literally hear it hissing and bubbling from there. I pulled the bolt closest to that area this morning, put sealant on teh bolt (it looked like it had some on in already) and replaced it. about an hour later I pressurized the system again, and got the same results. I will pull the cover and replace the whole gasket this week. From my description, are you fairly sure this will take care of the problem? I can't see the leak, just feel it/hear it. Thanks so much for your time!

[merc81]

If you think you can hear the air coming out in that area, then a new gasket will fix it for sure. Paint some permatex over the seam and see where it bubbles. How are you pressure testing the system by the way? How much pressure are you using?

I have many more photos of the timing chain cover removed and dirty/cleaned and I currently have an engine on the shop floor that I'm rebuilding, so if you want more details, ask.

It will be a tough job to clean the surface properly while the engine is installed, but work slowly and it will be fine when you are done.

[Adam M.]

Thanks, Merc-there's no think about it...it fizzes and bubbles, I can change the sound of it by putting my finger there. I'm using a coolant system pressure tester...hand pump. I pressurized it to about 14 lbs. lbs. apparently, I'll need a puller, and I need to use a floor jack to drop the subframe a bit to get the pulley off. Will I need to unbolt the entire subframe to drop it? I hope I'm not biting off more than I can chew...I'm not afraid to do it, I just have no idea what I'm doing!

[merc81]

Wow! Where did you hear you need to drop the sub-frame? There is plenty of room to take off the pulley; changing the main pulley is pretty easy. As an aside, if you move that subframe even half an inch, you are going to bend/buckle the steering shaft. The shaft must come off before you remove any of the frame bolts and to get to the steering shaft you need to pull off the air intake, the shifter linkage and the fuel lines are in the way and ought to go too, along with the thottle linkage. Don't worry about it, there is no reason to lower the frame.
Your main issue is going to be seeing down in there to do a good job scaping and cleaning the sealing surfaces.
Under the pulley will be the crank angle sensor and that has two 10mm bolts holding it on. I use locktite when putting them back on because I've seen them come loose and tear up the pulley grid.

There is also some concern that you don't damage the oil pan seal where it mates to the front cover (under the shaft). This area at least can be clearly seen and reached from the wheel well. Use a good razor blade and squirt the seal with pb-blaster to help it come free from the front cover. The seal should remain in the oil pan groove which you can clean with alcohol later on to remove the pb-blaster. With some RTV, the oil seal should be good as new when you are done. Just don't contaminate the RTV with the permatex. That's to avoid, but go very lightly with the permatex down near that oil pan seal and the RTV will setup OK.

[merc81]

In looking over this whole procedure, something that hasn't been mentioned is the coolant that will flow out of the block when you remove the front cover. Its quite alot really--the better part of a gallon I think. This coolant will flow right down into your oil pan when you pull the cover off. Its necessary to drain the coolant somehow before pulling the cover to avoid that happening. You could remove the screw in plug--that's right beside the oil filter in the block to drain the oil, or you could remove the waterpump (which would then need resealed) and work a drain hose back into the block and siphon the water out.

If I had to do this with the engine in the car, I believe I would go for the screw in plug that's up by the oil filter. An allen wrench should fit up in there without too much problem, you may want to remove the oil filter first. Then the coolant will flow out and drain the block safely rather than letting the water go into the oil pan.