560SL - Is the temp hot or normal - PeachParts Mercedes-Benz Forum

tivoliman · #1 03-06-2005, 01:25 PM

560SL 1986

Had the radiator replaced last year and some other engine cooling work done.

The engine seems to be hot at time - on hot summer days.

In a parade last October - the 560SL drove at parade speeds for 1.5 hours, with Junior Class representative sitting in the back

By the time the parade was complete - the engine was over heating with white smoke (or steam) coming out the exhaust.

At highway speeds - all well, but in the traffic the car heats up.

The temperature gage will occasionally "bounce" that is jump up and down the range.

Thanks for the help.

#2 03-06-2005, 02:27 PM

You mentioned other engine cooling work done. Could you be specific?

What you experienced at the end of the parade, overheating and white smoke out the exhaust is not normal. If it were a 98F day, with the A/C on, going up hill, you might get close to where it was that you describe and even then that would be doubtful!

If your radiator is still has the ability to cool coolant as it did 19 years ago, your thermostat is functioning properly, fan clutch, and electric aux fans are working properly, including aux fan thermo sender, good hoses, and fan belt tight, your engine shouldn't overheat and should guage around 80C or a little above.

One or more of the items listed above may not be functioning properly, or functioning in a diminished manor. Also, if engine timing is off, or if you have improper fuel mixture adjustments, these issues can also generate higher heat and if combine with the above will occur too!

deanyel · #3 03-06-2005, 03:21 PM

A bouncing gauge is not a good sign - you might want to deal with that issue first. With an accurate gauge you'll at least know how hot it's getting and how much of a problem you have.

Ali Al-Chalabi · #4 03-06-2005, 10:23 PM

What is the temperature that the engine is getting to? Verifying accuracy of the gauge if it is bouncing would be a good start.

Duke2.6 · #5 03-06-2005, 11:46 PM

Check the temp gage sender on the engine for corrosion and a snug fit. Intermittent high resistance could cause gage flutter. Also, an air bubble in the cooling system could cause the gage to bounce, but most air bubbles will eventually purge after a few hours of operation, unless they are REALLY large volume from a poor coolant filling technique. The gage will only be accurate if it is covered with liquid.

IMO driving in a parade is about the worst possible type of service. Idling for two hours straight is just not good for a car.

I've driven all my cars on racetracks at nine-tenths, but I would NEVER, EVER even consider driving them in a parade!

Duke

JerryWagner · #6 03-07-2005, 12:06 AM

If steam is coming out of the exhaust that is a very bad sign, it is a symptom of a blown head gasket with water entering the combustion chamber, you should check for oil in the water or water in the oil, if you pull the oil filler cap and it looks like a chocolate milkshake you have a blown headgasket or cracked head

#7 03-07-2005, 07:58 AM

Concur with Jerry..

white smoke coming out the tail pipe is a bad thing.

check to see if the white smoke is water vapor > take a kleen-ex and hold it in the exhaust gases > if it disenigrates >it's water vapor and probablly means that you have a blown head gasget = which is a case where the structural integrity of the coolant system [coolant kept in coolant passages] has been violated and the coolant is now mixed with the gas/air and oil lubrication systems >> not good...

tivoliman · #8 03-07-2005, 09:42 AM

The radiator was replaced with a new Behr.

The Thermostat was replaced with a new - forgot the manufacture.

Smile - The engine was replaced with a used engine - so the water pump came with that.

The white smoke has not reappeared since that "cool" day in October.

BTW - the air conditioning is not functional - there's a Freon leak, so no reason there to over heat.

The temperature sending unit is in my hands ready to be replaced - I purchased that to address the "bouncing temperature gauge".

Thanks for your support and assistance.

Does a water pump stop pumping water - or do they just die by leaking?

To address the "actual temperature" - I don't trust the gauge - but currently - cold weather - reporting normal 100 degrees or so.

Comment: In the cooler weather - the engine runs great, and stays cool.

Thanks again.

tivoliman · #9 03-07-2005, 09:49 AM

The radiator was replaced because the black plastic neck experienced "fatigue" and broke off.

realizing the challenge the thermostat would present with changing, I replaced it with the radiator.

Then the engine overheated - causing BIG problems - hence engine replaced.

The "new to me" engine is in now and when I was in the parade.

I pray to God, the engine does not over heat again.

Larry Delor · #10 03-07-2005, 11:31 AM

tivoliman,

BusyBenz had good suggestions... Check the clutch fan for proper operation (see if it freewheels or if there is some resistance). Also check the aux. cooling fans (fuses & relays). There is a elec. connector on the neck that the thermostat is under....if you pull that plug, it will force the fans to come on by default.
A hot engine, will usually smell hot....Can't describe the smell, but it does smell hot to me.
Also, after it has warmed up, and you are reasonable sure that there is coolant flowing through your radiator, turn of the engine and feel the radiator for cool areas which could indicate a blockage(s).

I have also read that some aftermarket rebuit waterpumps are not built to as close a tolerance as is needed. The rebuilts from MB however are fine to use.

Hope this helps, and good luck!

-Larry

tivoliman · #11 06-27-2005, 11:34 PM

found the water pump was leaking, the fan clutch was "weak" - that is some time it started - other times it didn't.

Magic renewed fan clutch, stopped water leak and now the car stays cool.

Enjoying the summer - top down often.

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