coolant loss with no drips?????

Gentlemen:

My 97 pa has started using coolant, no leaks, and some white exhaust. It seems to run fine, but over the past few months i've been adding coolant and can't find a leak. Do i need to replace the intake? and if so...is it a big job?
The vehicle has 130,000 miles on it. Any info would be greatly appreciated.

Northstar

Gentlemen:

My 97 pa has started using coolant, no leaks, and some white exhaust. It seems to run fine, but over the past few months i've been adding coolant and can't find a leak. Do i need to replace the intake? and if so...is it a big job?
The vehicle has 130,000 miles on it. Any info would be greatly appreciated.

Northstar


This is a problem to get to work on right away! To ignore could lead to a hydrolock of the engine or damage to the lower bearing (engine then toast). Probably the upper intake (plenum). A second one went bad on my 97 at 120k. Dorman makes a stronger replacement. Mechanics with reasonable ability do these in their sleep. Try searching for the past threads on this problem...a common problem and lots of information available. Usually the upper is replaced with the gaskets and PCV valve (plugs would be good too). It is also recommended to replace the lower gasket, and get a new lower intake with a smaller EGR stovepipe, or just replace the stovepipe with a smaller diameter one (the Dorman kit may include this). A sleeved upper intake can be purchased, or a sleeving kit from Ken-Co can be purchased, some owners sleeve their own intake. GM went to a smaller stovepipe in 99, this has helped but did not eliminate the problem. Again, start looking around, a very common problem...lots of info available on the bonnevilleclub site.

Bigsky:

Thanks for the info. I removed the intake plenum and it was burnt/rotted out. Had about a cup or so of coolant sitting on the manifold. I ordered a new dorman plenum and it came with the smaller pipe, i plan to install it this weekend. I've changed oil and cleaned everything up...hopefully theres no damage anywhere else. The plugs were pretty black and cruddy so i will swap them out to. Thanks for the input....i'll let you know how things turn out.

Northstar

Did your Dorman kit come with a new PCV valve? Just to mention, if transferring a PCV valve be sure not to miss the little o-ring. I saw a thread where some guys had missed the o-ring and had problems.

The smaller pipe will help. As mentioned, some guys install a sleeve in the upper which further helps to protect the pipe from the plastic upper plenum. The 3800 series III went to an aluminum upper...

Bigsky:

Yes, the plenum came with everything you need to make the repair. New pcv valve, seals, new fuel injector seals, gasket....its a pretty complete kit. Installed the new O rings on everything, flushed the coolant system, changed radiator hose's while i had it apart, cleaned up the injectors, new plugs and wires....it runs great....I havn't had it down the road yet, but it runs nice just sitting there.....ofcourse i had to erase the codes it produced when it went bad...."severe cylinder misfire" was the only code that showed up....plugs were soaked with anti freeze. It took a couple hours to put everything back togeather, it was an easier than expected...(never had a fuel rail off). Anyways....appreciate your help, and thanks for all the insight....

Northstar

"just a note"...are we talking "Bigsky" as in Montana? if so...i'm right across the boarder....