1992 Cadillac Sedan Deville issues

mmoshlak · #1 (**permalink**) 10-24-08, 04:26 AM

Hi everyone. I wanted to get an idea opinion of what could be going on with my Cadillac Sedan Deville. It's a 1992 Sedan Deville Front Wheel Drive model and I've had issues galore with it. Besides the repeat repair problems, I've noticed that it seems to be grouped around the radiator/antifreeze problems. Here's what's going on:

The radiator fluid/antifreeze is mysteriously disappearing from the radiator. With that I've had a number of issues including the replacing of the water pump between 3-4 times, the radiator baffles had to be replaced at least twice, minor hose issues, and the heater core blew four times within one year. The mechanic finally used a universal part after trying four heater cores. Now the fluid seems to be down with no visible leaks. Has anyone ever heard of this or seen this happen? A new mechanic I took it to concurred that maybe the fluid is leaking into the engine and being evaporated through the exhaust. He says he's seen it happen. Does anyone know anything? Can anyone shed any expertise light? I'm concerned the pressure may be a problem if the heater core, the water pump, the radiator, and the fluid is disappearing like that.

HELP!

Rodya234 · #2 (**permalink**) 10-24-08, 11:11 AM

The little plastic "T" joint where the coolant flows into the heater core may be cracked. It happens ALL THE TIME. My dad makes brass "T"s to prevent this, I'll wait for you to see if thats the problem before I get into that.

I_OnLy_RoLl_LaCz · #3 (**permalink**) 10-24-08, 11:25 AM

In my 92 deville the coolant was doing the same. I would have to fill it up at least once a day. Took it to the machanic and he said the head gasket was no good so fluid was burning up in the engine. Had another instance where a bolt was stripped out of the block and was causing it to act up and burn coolant and run like shit. Mechanic fixed it for about 150. Rethreaded the hole and but a new bolt in and replaced a thick metal plate. Some sort of gasket. Not to farmiliar with it. It was my first car didnt really know much than. Hope this helps ya out. My 92 deville was a BIG PROBLEM so i sold it and got a 2002. No where near as many problems
Good Luck

**Ranger** · #4 (**permalink**) 10-24-08, 11:26 AM

WOW! 4 water pumps and 4 heater cores? That thing is possessed. You don't need a mechanic. You need an exorcist.

Have the cooling system pressure tested. They'll pump it up to 15 psi and let it set for several hours. If the pressure falls, the leak will eventually show itself as it cannot evaporate or burn off, whether it is internal or external.

**Ranger** · #5 (**permalink**) 10-24-08, 11:30 AM

Quote:

Originally Posted by Rodya234

The little plastic "T" joint where the coolant flows into the heater core may be cracked. It happens ALL THE TIME. My dad makes brass "T"s to prevent this, I'll wait for you to see if thats the problem before I get into that.

Remember, that "T" has a restrictor in one leg. Be sure to make one for the fabricated brass "T" and be sure that it goes in the proper leg or you'll have heating problems.

Rodya234 · #6 (**permalink**) 10-24-08, 11:42 AM

He actually dose a very good job of making them. The first one has been in his white '93 for almost three years now with no problems at all

mmoshlak · #7 (**permalink**) 10-24-08, 03:26 PM

I know it's not the T joint. To double check, I looked at it today to make sure. No even when the system is looking sealed, the coolant is still evaporating. The four sources I know are a busted radiator, through the transmission (Service done today and confirmed no leaks), through the engine spilling out onto the cover, hose/joint issues. I believe all of those are covered. There's no leaks from the pump or heater core. However I found it real interesting the core, the pump, and the radiator tanks were replaced more than once in a five year span, indicating to me a potential pressure issue. Has anyone else had this issue?

I like the brass T joint idea very much. Where can I get them?

noahsdad · #8 (**permalink**) 10-24-08, 03:31 PM

Unless you're seeing or smelling coolant, it's gotta be going somewhere.

Go get yourself a Combustion Leak Test kit - I think NAPA sells them for about $25. You draw off coolant and put it into a chemical that checks for the presence of exhaust gases - works kinda like a home pregnancy test. If it's positive, you have a bad head gasket.

BTW, a blown head gasket can radically increase cooling system pressure.

noahsdad · #9 (**permalink**) 10-24-08, 03:36 PM

Another thought: you might also consider an oil analysis at your next change. They can detect coolant in the oil in parts per million. Blackstone Labs is a good company.

mmoshlak · #10 (**permalink**) 10-24-08, 04:05 PM

I just talked with Perfect Engine in Los Angeles based on what Rolz said and confirmed it. Apparently the bolt strips and causes an issue with the engine. Further the head gasket doesn't blow but it's not the best either. Cadillac came out with fixes for it. However the repair of fixing it is so expensive, that the tech said I should have the engine rebuilt under that situation. The whole thing will cost around 5K to have it done (3,500.00 for the engine, $1,500.00 for the labor)and take about three weeks because it's so labor intensive. I'll have it done because the car is esthetically in great shape, and the transmission plus most other things have been worked on. However it's going to wait until after next year's tax return check for sure! He also directed me to try GM directly to check for their engines as well. What a fix. The tech said at least it'll solve the issues at hand, and that's important. Ranger, do you know of anyone that can help? Anyone else know anything or anyone when it comes to engines?

Rodya234 · #11 (**permalink**) 10-24-08, 05:04 PM

That sounds a little expensive considering that you can get a 4.9L engine rebuild kit for $960.

Either way I wouldn't go for it, my dad purchased his new '93 with all the options (moonroof, CCR, etc) in perfect condition (no rust) for $950 plus $600 on shipping. 5k just for a engine isn't worth it considering you can buy a whole new car for $1500.

You could also try looking at your local junkyards for a car, and just pull the engine yourself or have someone do it for you.

mmoshlak · #12 (**permalink**) 10-24-08, 05:32 PM

See I'll do it because purchasing another caddy around that time means potentially inheriting someone else's issues that may be unknown at the time. I've been through this scenario much with this caddy, but at least I know what's been done with it and to it in order to assess the ultimate issues. Since the engine is the core issue, that's what needs to be taken care of. The '93 model was improved and doesn't have the engine issue. But so far I've already invested a good deal, and the warranty replaced a lot on it. So it makes sense to finish it out. Then if I have a good deal at the end, I have a good car with a rebuilt engine that has the issues corrected. From there on in, I should be good.

**Ranger** · #13 (**permalink**) 10-24-08, 09:41 PM

Can't say that I know of anyone that can help, but I am surprised. 4.9's are not known for head gasket problems.

mmoshlak · #14 (**permalink**) 10-24-08, 10:37 PM

Actually the head gasket is weakened from the stripped bolt problem that was mentioned. However according from the from the tech at Perfect Engine this bolt problem is a recognized issue. In fact not only did he say they're an issue that has a correction to it, he said that the engines are a pain the butt to rebuild. He said that the pull, rebuild, replacement, test, and run takes so much time he quoted me three weeks to have it back. That's why the quote it so high. I have a mechanic now doing work on the suspension and emission system. He recommended Jasper Engines, so I'm going to give them a try.

noahsdad · #15 (**permalink**) 10-25-08, 10:13 AM

I'd still recommend trying to diagnose whether your issue is a head gasket. It could be an intake, which is much easier and cheaper to fix - and in fact more likely. Ranger is correct that 4.9s don't usually suffer from HG failure.
The Perfect Engine guy is right that the 4.x engines are tough to rebuild. Once the aluminum block is released from the stabilizing force of the iron heads, it usually twists and warps, requiring serious machining to get sealable surfaces back. That's why Cadillac did not rebuild them in dealer service departments on warranty, they simply replaced the engine.
That said, Jasper does a good job of it. I've heard a number of success stories, including from my favorite grey-haired tech at the local Cadillac dealer. Actually, engine replacement in these cars is not that tough with a hoist and a couple of floor jacks. The engine support cradle is held in by four bolts and drops out the bottom.