So the mother in law has an 1998 Oldsmobile delta 88. It was given to her by her parents when they were living with them and couldn't drive anymore as they were getting too old to drive.

When I met my wife 6 years ago the car had sat on the driveway for some time until it aroused my curiosity as to why it wouldn't run. Then I started digging. Finally got it running after paying someone to fix an electrical issue.

I did not do any maintenance to it, but suggested things. Whenever there was a repair to be made I tried to do it unless I was not equipped.

Fast forward till now. The car was being used as a commuter car and pooling since we live 45 min from work and highway miles. Before this, it may have seen 15 min drives in town miles.

I noticed the windshield had a sticker saying it was due for an oil change. So I reminded the mil to get it done. Instead of taking it to her regular Castrol lube center, she took it to.... Wal-Mart!

Well these motors are fairly common for intake plenum gasket leaks and not changing the coolant doesn't help. Dex and green will mix without issue it just reduces the life of the coolant down to standard green coolant flush intervals. I don't really see what wal mart could have done to cause this issue.

Before you take the head off you should really do a leak down test, or bare minimum a compression test to save yourself some time/money just in case the HG and valves are fine. If it did hydro lock there's a fair chance something bent though.

These are pretty easy cars to work on so I wouldn't scrap it just yet if the rest of the car is in decent shape. It's been a while but I've done a few HG jobs on these engines so any questions feel free to ask.

Dex and green will mix without issue it just reduces the life of the coolant down to standard green coolant flush intervals.

 

Ummm... You might want to read...

 

http://www.autoblog.com/2009/12/28/coolant-color/

 

 

the two chemicals of Ethylene Glycol (green) and Dexcool (orange) are not compatible.

 

 

yea bad stuff happens when you mix orange and green.  Turns into this nasty "stuff", that is about the only was to describe it.

Sorry should have said that differently. Typically dex will turn into a engine clogging mess on its own if someone actually tries to get the stated 5yrs/1500,000 miles.

If a lot of glycol is added to the system then yes, orange and green don't play nice. I was referring to top offs which I know will go years without causing damage or turning to sludge.

I never have heard anything good about taking a vehicle to Wal-Mart. Not saying that there hasn't been any positives, but I've never heard them. So it put me on edge when I saw the sticker.

There is no way to prove if Wal-Mart did anything. For all I know they could have done a point inspection like lube centers do when they do an oil change and topped it off with green coolant.

I tried to do a compression test but like I said my tester hose wouldn't fit into the port. The exhaust manifold blocked me.

If something bent, I put money on push rods. I'll check them.. I spent 6 hours on it last night tearing into it, I have the right head off and then called it quits for the night. It's absurd how much needs to be removed to get to the engine.

I need to know what I can use to clean everything. I've got a pressure washer, purple power degreaser, dawn dish soap, hot boiling water...

How can I get the cylinders cleaned out and any internal areas? There is sludge buildup and to me I would like to see a rebuild since it could get hot tanked then...

The current coolant flushing cleaners suck now adays...