I need the help of some real car buffs

[Ritalin Kid]

Ok I feel real silly asking this here but it seems like the only place where I can get some real answers..

I have a 1984 Cadillac Coupe DeVille, V8 Digital Fuel Injection, I just recently bought/traded for this car.. I have put a new themostat on this car and the radiator and water pump are fine.. and there are no signs of leakage of water under the car..

WHY IS THIS CAR OVERHEATING?!!?!?!

It has also had a full tune up of plugs/wires/distributor cap/and Rotor button.. and the car still stalls out like it's being flooded especially when it shifts into 2nd gear.. unless you slam on the gas and then the car takes off..

So now the car is both overheating and stalling out.... please someone who has some advice please help me out here..

[surrealchereal]

.. Unless you slam on the gas and then the car takes off. You mean just push the accelerator, slam it or tickle it cause it's gasping for air? Are you sure the two are related?

[krusty the klown]

Just a couple of basics:

Are the radiator fins clogged/corroded?

If it has an electric cooling fan, is it cutting in?

If it has an engine-driven fan (with viscous coupling), is the viscous coupling knackered? (with the engine hot, does the fan speed increase with increased engine revolutions?)

Is the engine running on the correct grade (Octane rating) of fuel?

When they 'tuned' the car, did they check the air/fuel mixture - too lean & you can start to run hot. Also, did they check the ignition timing?

On a modern car, the latter two will be adjusted 'on the fly' by the car's ECU.... I'm not sure how sophisticated ECUs are on 'St8side cars of that age, so it may or may not apply.

[cedar2]

If your transmission is running hot it can cause overheating on many vehicles of this era because a transmission fluid cooling element is incorporated into the rad. If yours does, it will have two small inlets at the bottom of the rad with lines leading back to the trans. Trans overheating can be caused by bad adjustment of the bands, low or dirty fluid and a variety of other things.

[Sweeper]

and there are no signs of leakage of water under the car..

Have you had the cooling system pressure tested to see if there is an internal leak?

Sweeper

[prexaspes]

Adjust the timing.

[jad1097]

"Best bet is to take it to a GM dealer who can check it out the RIGHT way.." should read: Best bet is to take it to a GM dealer who will rip you off.. http://www.sysopt.com/forum/wink.gif

[Ritalin Kid]

Probably so I'm pretty sure that the Radiator is fine.. engine fan is good.. water pump good.. the TPS and the EGR valve (of which I never was aware of) are two things I never mentioned and the Oxygen sensor are all things I never even knew to think of but as far as a GM dealer I might be stuck with no other choice because I live in a small redneck town in TN where they believe that Lucas Oil Treatment can cure what ails any car..

I currently have it at a shop where I trust the guys.. but if they happened to get stumped I will run these across them just to see what they say.. Only GM dealer close to me is Skinner's Chevolet and from what I hear he's not the cheapest place in town to get anything.. so I will keep my fingers crossed and I'll let you know how everything turns out..

[This message has been edited by Ritalin Kid (edited 06-07-2001).]

[Richard_Cranium72]

Cedar and Krusty have covered several points.

On the sluggish behavior several things may occur.

The Throttle Position Sensor(TPS) WILL cause this, check with an ohmmeter for smooth change in resistance.

The EGR valve if stuck open will cause rough idling, start and stop on cranking and hesitant running AND can cause the timing to self-retard causing extreme heat in the engine.

A bad Oxygen Sensor will/ can cause overheating and will damage the engine from excess/lean fuel mixtures.

Best bet is to take it to a GM dealer who can check it out the RIGHT way..

DrVette

[Richard_Cranium72]

As my ol Daddy said regarding Union workers(he was NOT union)

If you want the job done right, and done right the first time, call a union contractor.
It will cost a little more, but they KNOW what they're doing.

Much the same at a LARGE dealership. Some little town dealers are no better than a mom & pop at figuring out problems. Your best bet is a dealer who has more or less an honest reputation.

We have 2 large GM dealers here. ONe rip-off or at least a Azz hole for an owner.
The other is a knight in armor , compared to the other anyway.

Dealer pricing on parts have dropped over 50% in the last few years due to the "Junkyard" stores such as Autozone, Advance, Pep Boys, NationWise etc.
These stores sell "Lifetime" warranty on parts that often fail upon installation.

What savings is gained by paying labor time and agian for new DEFECTIVE parts. We all know that labor is usually the largest portion of a bill..

good luck

DrVette

[Richard_Cranium72]

BTW, is the motor in this car the 4.1 litre engine ?

[stewartmann]

ok well my car is only an old bomb..but hell it was over heating just the same...no visable leaks whatever....
i changed the head gasket and ..presto, no more over heating

[Ritalin Kid]

Yep that's the one 4.1 Digital Fuel Injection.. I got my results back and they said that it could be either the heads themselves are cracked or the head gaskets are gone they said they can't tell for sure until they get to breakin the engine down.. the worst part is that it's gonna cost me $780 for all the work (this includes having the heads resurfaced by a machinist) and maybe $30 more for a used head if it turns out to be a cracked head. Oh well anybody gaskets please tell me how I can check myself wanna start a donation collection? :P If anyone knows how I can tell if it's just the head gasket let me know.. I need to know for sure if it's the heads or just the head gaskets.. only symptom I have seen is that only one Valve Cover Gasket is barely leaking and the other side is fine... if this helps clue anyone in speak up.. thanks for the help..

[ragtop]

If the head gasket is leaking, or the head is cracked, you will normally see one or more of the following: 1) Oil or water leaking from between the head and the block. 2) Oil in the radiator. 3) Water in the oil (makes the oil look kinda like a chocolate milkshake). or 4) White steam coming out of the tailpipe.

Actually, $780 including milling the heads is a pretty good price - there's a lot of work involved.

[jad1097]

Very true Doc but I have seen some real rip off dealers in Miami back when I was a mechanic. Of course the guy that taught me the proper way to work on cars got his training while working at a dealer and he sure had some stories to tell about the scams they made him run. You know the kind, like squirting oil under the car and then showing the customer.


I am still waiting to find a mechanic I trust other than my buddie who lives 995 miles away. http://www.sysopt.com/forum/wink.gif

[Atomic Rooster]

ragtop -
Not necessarily. My Taurus had a blown headgasket with none of those symptoms. It was just leaking pressure into the radiator, no oil. Took me the longest time to figure out why I had to keep putting water in the radiator when the overflow reservoir was always full. DOH! $780 isn't bad at all. It cost me $1200 for the same work, and the mechanic is a friend of my Father-in-Law. But then, I do live in California.

[jad1097]

Oh, as an example of the kind of shop I worked for I will tell you this story.

A women has her car towed in because it overheated, blown head gasket and cracked head. I fixed it.

She calls a few days later, overheating again. Ran a pressure test on it and a freeze plug had developed a leak, pinhole. She jumped all over my boss, he then told me to change all the freeze plugs out, I did. She came to pick the car up and he handed her the keys and told her there was no charge and not to ever come back again because she was rude and it was not our fault, etc...

Whats she do but come back a month latter for something else with a changed attiude and was very thankful. She also recommened us to all her friends and co-workers. But when she brought her car back it still smelled of cat urine, yuk!!!


Anyhow that is an example of an honest mechanic and a dealer would not do anything such as that AFAIK. North Dade Shell gas station on 441 and NE 191 st in N. Miami, FL, Joe was the owner and Andy, my buddy, was the head mechanic. Me, I was just a helper but could R&R anything fast and correctly. I sure miss that job even though the three of us worked 12-16 hrs. a day when work was good, had to get those cars out of the bays. http://www.sysopt.com/forum/wink.gif

[Gomer]

What made them think it was the head? Also, run to autozone and buy the Haynes Manual for that car. Most GM porducts of that era allow for a simple diagnostics using a small piece of wire. The book will explain it to you pretty clearly. Or you could just ask them for the "CODE key" and book. They will give it to you for free. That won;t tell you if it is a bad head, but it will tell you if you have a problem with your emissions system (EGR, TPS, O2 etc.)

Jad: Boy am I familiar with that song and dance. I worked as a clerk/ light mechanic for a few years at a nearby garage. Since I was the one who had the phone in my hands most of the time, I caught the brunt of those sort of things. Not fun.

[socalgal]

Moved to Community http://www.sysopt.com/forum/wink.gif