Need info on possible purchase

[drhook]

I am looking at a 92 caddie wil the 4.9 53,000 miles. What can you tell me to look out for? Is this a good car/engine

[Scotty]

I had a 91 Seville with a 4.9. The car has on-board diagnostics that you can access by pressing and holding the OFF and WARMER buttons on the DIC. The system is OBDI and you can read real time information, override parameters and perform diagnostics.

The 4.9 is a terrific engine, I loved it.. I am looking for a 92 Eldorado for my son, JUST to be involved with the 4.9 again.

If you don't know already, there is a lot of information in the archives on the 4.9. Feel free to ask questions about it however. My experience with the 4.9 that I owned for 5 years is as follows:

1) the engine can suffer from a #1 main bearing knock. It was made louder by synthetic oil and it was quieted down by Delvac 15W40. The knock it not serious at all just an annoyance. The knock is more obvious in the summer months and when the engine is very hot.

2) the EGR system will give off an E048 CODE at times, keep the tubes down the throad of the TB clean, check the vacuum hoses and clean the EGR.

3) the engine is prone to detonation if the EGR system not working properly, it occurs on light pedal acceleration and should not be confused with pre-ignition. My detonation was ultimately solved by replacing the EGR.

4) the oil cooler lines at the radiator and oil filter adaptor have o-rings on them that must be replaced once the line is opened especially if they are old or if they are leaking, as they dry rot, crack and not longer compress. If you are leaking around the oil filter adaptor there are o-rings behind it also, that can be replaced.

5) Keep and eye on the plastic T in the heater lines in the center near the firewall. As it gets older it can develop cracks, WATCH how it is oriented there is a metered orfice that must face in the right direction or you will get poor heat.

6) use the GM cooling supplement in the proper amounts!!! VERY IMPORTANT. Change the coolant on schedule and use a 50/50 mix of coolant and distilled water.

7) The water pump does not give a lot of warning when it goes bad, if you see moisture coming from the weep hole consider replacing it.

8) Recently we have been having some driveability issues due to bad grounds and PCM's that needed replacement.

9) the CAT can go bad and it rattles loudly when it begins to go bad. It sounds like a heat shield is loose.

10) the end tanks on the radiator are plastic and as they age they develop cracks, I replaced mine with an OEM AC Delco, but you can also have the plastic tanks replaced..

That is my experience with the engine. Its a workhorse!

[drhook]

Thanks for taking the time to share the great info. I will take a print with me when I go look at the car tonight. It is spotless but I don't know the story yet.

[ted tcb]

Great info, Scotty.

The only thing I would add is that some of these cars have a problem where the accumulated brake dust sits in the engine cradle, by the motor mount, and rots the metal.

I lost a motor mount when my metal cradle disintegrated ... the welder told me he has seen this over and over with the Cadillac, Buick, and Oldsmobile bodies.

You can tell by the vibration at highway speeds ... basically, my engine was lobsided on one side. This was a very expensive fix on my 89 Fleetwood fwd.

[bigjayzway]

3) the engine is prone to detonation if the EGR system not working properly, it occurs on light pedal acceleration and should not be confused with pre-ignition. My detonation was ultimately solved by replacing the EGR.

Amen to that Scotty.

I think that is the #1 issue I have delt with.

Other than that, I miss driving the 4.9.

Since I baught the STS, I took the insurance off the Deville.

I'll tell you one thing. I got better milage on the 4.9 than I do the 4.6.

Mostly cause I honk on the STS every chance I get, and the Deville I babbied it.

Big Jay

[67coupedeville]

9) the CAT can go bad and it rattles loudly when it begins to go bad. It sounds like a heat shield is loose.

Drhook, thanks for asking about the 4.9, something has been rattling (sounds like a heat shield) ever since we got our 91 Fleetwood. I'm going out right now to take a look at that.

Our 1991 Fleetwood is bulletproof (mechanically). We bought the car in 2003 and the only thing that does not work on ours is the A/C. Our 4.9L starts on the coldest winter days and nights here in Southern Saskatchewan. I have not noticed any bearing knock that other 4.9s are proned to. We did replace the front stuts with aftermarket KYB struts. I can't really think of anything other than what Scotty said to look for. Great cars.

Spence

[Scotty]

9) the CAT can go bad and it rattles loudly when it begins to go bad. It sounds like a heat shield is loose.

Drhook, thanks for asking about the 4.9, something has been rattling (sounds like a heat shield) ever since we got our 91 Fleetwood. I'm going out right now to take a look at that.

Our 1991 Fleetwood is bulletproof (mechanically). We bought the car in 2003 and the only thing that does not work on ours is the A/C. Our 4.9L starts on the coldest winter days and nights here in Southern Saskatchewan. I have not noticed any bearing knock that other 4.9s are proned to. We did replace the front stuts with aftermarket KYB struts. I can't really think of anything other than what Scotty said to look for. Great cars.

Spence

Spence, if you have a rubber mallet, hit the cat with it to illicit the noise, Mike

PS, did you ever listen to the tape?

See these threads:

http://caddyinfo.ipbhost.com/index.php?sho...l=rubber+mallet

http://caddyinfo.ipbhost.com/index.php?sho...l=rubber+mallet

http://caddyinfo.ipbhost.com/index.php?sho...l=rubber+mallet