Still overheating (grrrrr!)

[Andrew116]

Hello there michaeld!
I had a similar situation with my 116... never stepped in one until 6 months ago. One moth after I bought it, it started leaking cooling fluid.
After taking a close look to the hoses the waterpump was next. I noticed that from one of the holes in the pump water was leaking.
It's the first time I take a look at this type of engine (280SE), but as I told styria I grew between Diesel engines, an my father has agricultural tractors and waterpumps were allways a problem. In my case I replaced it (alone ) in 2 hours. About your overheating... we here use Celsius degrees not Fahrenheit, but I know that the coolant is important... I use water with 2L of antifreeze - so my engines stays allways at about 85oCelsius even if outside are 40 and the traffic's a mess. Now, if you use 30%-40% of antifreeze your engine works at a higher temp. (about 95-105 C) And it's OK because the boiling point of the coolant mixture (if you have between 35-45% antifreeze)is around 115-120 degrees Celsius. The overheating of an engine means that the coolant reached the boiling point and that is bad why??? ... because inside the engine block, vapors are starting to create which means that the cylinders will no longer be surrounded by coolant only, there will be also air. So they'll start heating up fast and burn the oil in the engine. By the way... did you checked the level oil and the pressure?
Enough with the talk As long as the fan spins... is OK! ...if U have a working water pump. Problem with water pumps is sometimes the inside propeller (don't know how else to name it in English  ) of the pump, loses it's grip or block pin - if it has one - and starts working independently, in other words your fan spins, your alternator too, but the water doesn't move around.


So I suggest you loosen up the the driving belt which spins the fan, take of the thermostat and manually spin the water pump and U can see if it puts the water in motion or not.

Hope U solve the problem... OH!!! did U checked if there is any oil marks in the coolant??? Because that means You've got trouble.

Waiting for your progress... and don't give up!

[michaeld]

I've kind of been like the U.N. moving on the nuclear program in Iran; you know, at glacier pace?

I don't drive the car overly much, and just haven't had enough of a feeling of a problem to put my gluteus maximus into gear and move on this.

I still wonder if I have a failing gauge.  After reading your post, I WILL make sure that I'm not weeping at the water pump, but that didn't seem to be a problem when I was working under the car doing the thermostat change.  I DO seem to have a very tiny leak in the system, but it's weird: I have filled the expansion tank several times, and then noticed that the "cool" level was down about an inch.  It's never gotten below that point.  Furthermore, I NEVER had this issue until I changed the fluid.  A mechanic told me that he thought this was just part of getting to the correct level after a fluid change (that it would take several burpings to get to the 'just right' point).  The car has been looked at by three different mechanics, all of whom said I didn't have a problem.  However, none of them have REALLY gone through the system and done all of the tests; they just let it run for half an hour and looked/felt it over.

In terms of connecting a second gauge (at least to check/verify the temp), does anyone have a nice good place on the block/head that gets water?

I am running a 50/50 blend of antifreeze/distilled water, which DOES run hotter than straight water.  I live in a desert and park in a garage, so I don't have to worry too much about freezing...  I considered switching to a low mix of antifreeze and using Water Wetter,  but I JUST replaced the antifreeze, and not only am I lazy, but cheap as well!

Other than the connecting a secondary water temp gauge, my next project would be to do a compression and vacuum test to see if anything is going on.

It's irritating, because the car seems to be okay, but I don't fully trust it until I KNOW what has been going on.  I also haven't wanted to risk pushing a system that had a problem.  So I've kept my driving down - which is 116 abuse.

[Andrew116]

Well, michaeld,seems that you might just have told me the problem.
You say U use a 50-50 combination... well in the car's manual, the car comes from factory with the next recommendations:
55% water - 45% antifreeze: for temps. down to -30 degrees Celsius (with a boiling point up to 125 Celsius)
70% water - 30% antifreeze: for temps. down to -20 degrees Celsius (with a boiling point up to 115 Celsius)
In hot areas (you mentioned something about desert???) it is possible to use only water to drop the temperature to 85-95 degrees but mixed with anticorosion oil 1% of the coolant's volume.
Recommended that the change of the coolant takes place once every 2 years (no matter the number of kms)
Very important is to not have any air in the cooling system!
Hope I'm right and you solve the problem... the easiest thing would be to let about 1-2 litres out of the cooling system and fill it up with water.
Feel free to try and reply! 

Andrew

[michaeld]

Andrew,
Just noting your location.  It's neat to be "talking" to someone from Romania.  The closest I ever got to your neck of the woods was a trip to Budapest (I went to both sides of the river just so I could say the whole name!).  As a native Californian, I can say that there is a distinctly different "vibe" from old world eastern Europe that I really enjoyed.

You know what?  I'm going to take you up on what you're saying.  One question: would using this "anticorrosion oil" be better or same-same as using Water Wetter?  Water Wetter cools  a system down 20 degrees F with water alone, but only about 8 degrees w/ a 50/50 blend.

I changed the rad fluid about two months ago, but to dump a fairly small amount and replacing w/ distilled water (plus oil/Water Wetter) sounds reasonable.  I live in Palm Springs, CA, which gets to over 120F (i.e. over 49C) in the summers.  In the winter, it very occasionally actually gets cold enough to frost/freeze (say about 30 F), but I certainly don't need "maximum protection against freezing."

[michaeld]

Sorry to keep dragging up old posts, but I've got a little update...

First of all, I took the car to a friend who recently retired as the owner of a transmission repair shop.  He took out his thermocouple and multi-meter and - after placing it at various points (the water pump outlet, radiator, expansion tank, 212F switch) - pronounced that the car is running at a normal temp.  His conclusion: the guage (which was reading 240F) is reading incorrectly.  He thinks its off by a good 40 degrees.

I did much the same thing some time back with my laser infared thermometer, but wasn't sure how much I could trust the readings.  Jim's $500 multimeter w/ thermocouple probes pretty much tells me that my readings were right.

Secondly, I went ahead - even after the above event - and replaced about 1 3/4 gal of 50/50 mix with straight distilled water and added a bottle of Watter Wetter.  I figure my new ratio is about 30-35% anti-freeze.  When I took two 60 mile drives yesterday, the (now untrustworthy) gauge showed the temp was down a good 20 degrees F.  The stuff really works!

I would go ahead and add the "anticorrosion oil" to the coolant, but haven't seen it in the stores.  In any event, I hope the antifreeze in the system is enough to reduce corrosion.

I had a "freak-out" moment after the above change: as I was topping off the system, I noticed some little dark globules.  My heart sank as I wondered whether - in spite of my mechanic-friend's assurances - that I had a blown head gasket that was finally revealing itself.

This morning I went out and captured one of those globules and put it on a napkin.  When I examined it, it was green, not black (WHEW!!!).  I'm not sure what it is; I haven't seen it until now.  But it's got to be coolant (or a Water Wetter reaction?), not oil.

Now here's another question: Do I have a bad gauge, or a bad water temperature sending unit?  If a bad sending unit, I'll replace.  If a bad gauge, I'd probably just re-connect a tasteful gauge down below (assuming I can find an aftermarket that fits up).  Has anyone had any experience with this?  I can't even imagine trying to reach into my dashboard to replace a gauge!
Mike

[jjccp]

Mike,

The instrument cluster pops out as one unit. It's pretty easy/hard depending on your patience level. I took mine out earlier this year to replace all the bulbs. It was my first time and it's wasn't hard at all once you know the tricks.

The following link is for repairing your speedo, but it shows how to get the cluster out.

http://dieselgiant.com/repairyourodometer.htm

Glad you finally found the problem. This topic was getting too long anyway. Just kidding.

Jim

[michaeld]

JCCP,
Thanks for the link.  I copied/pasted it so I can refer to it.  I had envisioned trying to get my very big hand up into some tiny crevice behind the dashboard, and my heart quailed from fear at the prospect.

I'm still somewhat suspicious, but I've now had three mechanics tell me the system was okay.  It's never boiled over, or shown any other signs of overheating other than the gauge reading.  Also, I've never seen any indication of a head gasket leak (white smoke, oil in the coolant, yellow gunk in the oil cap).

I'll probably go ahead and replace the water temp sender unit, and if that fails, work on replacing the temp gauge.

Mike