1997 3.5 Chrysler Concorde overheats and loses coolant/pressure somewhere?

Question

I'm afraid it's a Head Gasket. The car runs great when 1st started but will overheat and the reservoir will empty itself.

I cannot see where the fluid is going, if anywhere outside the engine. Oil is Black, but need a definitive test to determine if blown head gasket?

Weird that if it's blown head gasket, would it not run rough?

If it is blown head gasket, it's not worth fixing, according to a mechanic or two that I've spoken to.

Apparently the 3.5 dohc is a real bear to repair and aluminum heads.

Any help out there? Any Suggestions where to start? I'm a backyard mechanic with medium skills and tools.

thank you, Dave in Nashville, TN

wow! thanks for all of the replies!

If it is a head gasket, can the engine be fixed? Aluminum Heads and all?

thanks again!

Answer 1

You've pretty much answered your own question. A blown cylinder-head gasket will result in a veritable cornucopia of symptoms. Depending upon how bad the leak is, anything from no symptoms at all, to an audible change in exhaust tone can occur.

A repair facility can diagnose a blown head gasket for you. The procedure is called a leak-down test. This is where the engine is filled with compressed air, and then a reading is taken based upon how long it takes for the internal pressure in the engine to return to atmospheric.

Also, the color of the crankcase oil is not usually affected by coolant-contamination. The crankcase oil level, however, WILL be affected. If you have a blown head gasket, coolant will contaminate the crankcase oil, and produce a level reading that is too high. You can of course check this yourself with a simple reading of the dip-stick for the crankcase oil. Is the level way too high? If it is, you've likely located a bunch of your missing coolant, no?

Furthermore, if this is the case, there will be crankcase oil floating on top of the coolant in the actual radiator. If the missing coolant is absolutely, for sure, not in the crankcase, then you might start trying to direct your diagnosis in another direction.

The aluminum head on that particular power-plant is a sensitive little bugger. Over heating will quickly warp, or break it. Now that you have had over-heating issues with this engine, I'd be very weary of putting a bunch of money into it. If you have a head-gasket leak, and you choose to repair it, make sure to have the block resurfaced, and purchase a new head, rather than resurfacing the old one. The cost of which will be comparable to putting a good used engine in it, or simply replacing the car.

This is 100%, absolutely, NOT a shade tree job. Whatever your decision, you will likely find that you simply lack too many of the necessary tools for this job.

In answer to your question: Check the crankcase oil level, is it way too high? Check for crankcase oil floating on top of the coolant in the actual radiator. These are tell-tales of a cylinder-head gasket leak.

Answer 2

hey man check to see if the fans are running we jsut had 2 cars on my block with that prob the steam has to go somewhere check to see if the car has a remote bleeder set up for coolant looks like a bleeder screw for brakes but mounted on the eng (usually in the intake) Is there alot of water vapor going out the tail pipe ( Head or gasket) you also could have a water pump that the impeller (fan) which is pressed on works with eng cold but slips when it warms up you can go to alldata.com (I go to the libary its free) With the eng running feel the upper rad hose do you feel the water running thru it start cold then keep checking to see if it warms up and pressure builds in it as the thermostat opens also go to a parts store like oreillys autozone and rent a radiator pressure tester and put it on before you start it up if it dont read what is on the rad cap something is screwed thermostat/ water pump. also look for a collapsing hose look at a hose and rev the eng up a couple k in rpm and see if the hose goes flat if it does the hose is bad. one more thing if you have an automatic xmission check the fluid in it if there is water there the rad is cracked interally Alot of cars nowadays use a coolant sealant from the factory My caddy requires it check all the above if you cant find any put a good alum sealant in a see if that fixes it good luck

Answer 3

I don't know what reservoir you mean. The radiator top tank or the overflow container. I believe you have a plugged radiator. With the engine at operating temp. turn off ignition and CAREFULLY put your hand on the radiator core. It should be HOT. If you feel any places that are cooler you have a plugged radiator. A radiator shop is your only answer. Don't try those chemicals they sell at the parts store, they won't work. You should be able to remove the radiator and take it to be cleaned.

Answer 4

you can do several things to check for blown head gasket check your exhaust to see if you have excessive mositure also do a compression check and check each clinder agains t the other thay are senitive heads and as long as you hav'nt overheated it severly you can repair it just be very careful as you dont strip the bolts get a chilton or haynes manual good luck

Answer 5

sorry but the 3.5 engines like to crack heads. Hope it is the head gasket as it is cheaper.

Answer 6

my money is on bad head gasket

Answer 7

well i have had the head gaskets replaced, new radiator and i continually have this issue.............. it has to be somnthing more