High Engine Temp! Need Help Asap Guys! - Page 5 - PeachParts Mercedes-Benz Forum

#61 07-17-2002, 11:12 AM

If you are thinkng of trying the rad substitution test - go half way - pull your rad and fill with hot water as I suggested previously and feel for cold spots. Do the same on the other rad - if the other rad doesn't have cold spots - buy a new rad or get it cleaned. It would be simpler than taking out installing and taking out and installing again.
Just my thoughts
Maurice

DJNEWK2 · #62 07-18-2002, 09:15 AM

Flushed the radiator last night and noticed that is was pretty clogged with little white particles inside on one side and had some feathers in the fins that washed right out...I also reverse flushed and found that it was flowing well when I finished. I reinstalled and ran water into the hose from the bottom to see if it would flow out of the top outlet which it did. All was cool (I thought) but when I filled the upper hose inlet going to the water pump, the water didn't go down and just sat there and got hot.

Shouldn't that water go down to be circulated back to the radiator? Then I heard the water pump squeaking for a few seconds and then it stopped, but as I said, the water just stayed in the hose and started to get hot and no water came out of the upper radiator outlet. So far she's run at a fluctuating 82-100 and no coolant loss. Does 100% water make the engine run warmer or cooler? I thought it was cooler but not sure. I haven't added AF because I've already wasted one container of MB coolant since the t stat change and want to save the other until I've licked this. Does this sound like the water pump or ??? Would it take almost 20 minutes (like it did this morning) for the temp to go past 100 if it was the water pump? Man oh man what's next!?

#63 07-18-2002, 09:26 AM

Take the rad to a Rad Shop and get it professionally cleaned and checked - I really think that will solve your problem. There are many raceways for the water to go from the bottom to the top -if some of them are plugged - water will still flow - but you will still run hot - save your aggrevation - get a pro to clean the rad and guarantee it is clog free. I am confident it will cure your heating problem.

DJNEWK2 · #64 07-18-2002, 09:40 AM

I agree Moe and that is next on the list... I've been trying to locate a behr radiator at a decent price because I believe them to be a better constructed radiator than the Nissens I have.Also, what about the water pump issue? Any opinions welcome. The radiator shops I've called so far say they can't clean it because they can't take it apart (but I'm sure SOMEONE can take it apart) so I'll have to just keep trying...Thanks for the advice so far and feel free to keep em coming!

#65 07-18-2002, 09:51 AM

I'd leave the water pump for now. When you get the heating problem fixed - add some water pump lubricant to the antifreeze and it will stop the squeal. If the pump was bad - you'd have overheating all the time (worn out vanes - broken vanes would be clanking in pump) or it would be leaking - so I'd leave the pump and get the rad done.The chemicals they sell for DIY are not strong enough for real bad clogs. If they say they can't clean it because they can't take the top and bottom off to rod it - look for another shop - up here in no-man's land - there are shops that have the gaskets and expertise to remove the top and bottom plastic covers and replace them - there must be one down there. Be advised that it might be cheaper to buy a new rad then pay what some of these rad guys want for cleaning. I checked out the price for my 1930 Chevy rad CORE ONLY - not soldered to the top or bottom pieces - $500-700 USD! Mercedes is sounding cheap for rad prices now!!:p :p :p

DJNEWK2 · #66 07-18-2002, 10:55 AM

Believe it or not I actually found a NEW Behr for $219.95! Hopefully I will get time to be able to put the original radiator on her before the weekend so I can see how she acts and if all is well, definately get the new Behr that the dealer says should be here from Florida in 2 days tops for $10-$11 shipping. Hell I paid damn near this much for the Nissens I have ( I should buy two-- this guy doesn't know if it has the reinforced neck but whatever...the place I bought my Behr from for my other 560 that's sold by the way is history)! Man I'm hoping this isn't a head gasket (even if its a small leak not detected before) but there's no water in oil and no oil in coolant so God is looking out for me on this one.

Mike Richards · #67 07-18-2002, 12:32 PM

DJNEWK2:

A few days ago someone posted here that the new Behr's do not contain the reinforced neck. I see you picked up a new radiator for just over $200. Not long ago the reinforced models were closer to $300.

Please post back here whether this $219 rad. came with a reinforced neck. Thanks.

DJNEWK2 · #68 07-18-2002, 01:36 PM

Will do, but at this point I'm thinking it took 14 years for my original's neck to break so if it isn't I'll live considering I've only had the Nissens about a year and already have issues (if it is the case). The old Behr still works fine and I can actually hook up the hose to it but not as secure as when the neck is how its supposed to be.

I took the car out for lunch and so far its running at temp 80-84 in town but very erratic shaking at takeoff smoothing out as I get speed (but still crappy gas mileage). Wouldn't a leaking head gasket also cause rough running? If the radiator swap doesn't work that will be what I'll have checked (again just in case its acted up from the high/low temps). Just paranoid right now because I hate not having it definately pinned down yet. thanks a lot guys

Alan

jsmith · #69 07-18-2002, 02:01 PM

a couple of times you've mentioned that the aux fans kick in at high temp but you always say you switch it off then - what happens if you let it run? the high speed fans should cool it down then eventually switch off. they should already be on by the time you hit 110C. if you switch off then the heat soaked engine has nothing to draw off the heat and the temps will climb even higher and possibly cause the release by the pressure caps in the overflow tanks. if you have plain water in there, it will be easy to cause this as the boiling point is lower. i did see that you mention that coolant makes it bubble over more easily which is the opposite of what i expected. i would tend to suspect the themosensor that triggers the high speed fans. i believe they should come on before 110C at which point temps should start dropping rapidly...

ctaylor738 · #70 07-18-2002, 02:02 PM

I started reading this thread and couldn't stop. I will refrain from offering advice - you have plenty of that. But the whole issue started when you went from water to 50-50. Here is a possible explanation from the Red Line (make Water Wetter) web site.

Good luck!

"Red Line WaterWetter® can reduce cooling system temperatures compared to glycol solutions and even plain water. Water has excellent heat transfer properties in its liquid state, but very high surface tension makes it difficult to release water vapor from the metal surface. Under heavy load conditions, much of the heat in the cylinder head is transferred by localized boiling at hot spots, even though the bulk of the cooling solution is below the boiling point. Red Line's unique WaterWetter® reduces the surface tension of water by a factor of two, which means that much smaller vapor bubbles will be formed. Vapor bubbles on the metal surface create an insulating layer which impedes heat transfer. Releasing these vapor bubbles from the metal surface can improve the heat transfer properties in this localized boiling region by as much as 15% as shown in Figure 2. This figure demonstrates the removal of heat from an aluminum bar at 304°F by quenching the bar in different coolants at 214°F under 15 psi pressure. Compare the time required to reduce the temperature of the aluminum to 250°F, or the boiling point of water at 15 psi. WaterWetter® required 3.2 seconds, water alone 3.7 sec, 50/50 glycol in water required 10.2 sec, and 100% glycol required 21 sec. Water alone required 15% longer, 50/50 glycol 220% longer, and 100% glycol required 550% longer."

DJNEWK2 · #71 07-18-2002, 02:20 PM

yea the aux fan kicks in like its supposed to.I was saying that when you shut off the car, the fan also stops so I shut the car down and then turn the key back on so that the fan continues to blow until its below 106 stopping the fan. Now I always do that if it kicks in and leave it on and lock the car with the other keys (returning about 5-10 min after the heat dissipates to get my key out).

I've also used the water wetter to no avail (back then when it was boiling and spitting the coolant back out but now the coolant stays put for the time being since I changed out the expansion tank,hose and cap). I'm wondering if anyone is familiar with where the coolant holes are on the block if these have them.Someone on an earlier post says it could be air trapped and I don't think their was a 560 so this may not apply to my car.Also need the location of the exhaust valve on this car (for something else). Thanks

Alan

Mike Richards · #72 07-18-2002, 02:39 PM

DJNEWK2:

I too have a 126 gas car, but with the smaller 6 cyl engine. I recently resolved an air-in-cooling system problem following some advise I found in a post from back when. The process applied to a 124 car, but it has essentailly the same engine as mine. I cannot say if this will help a 560. Perhaps those versed in this engine will add to what I have here. Here's what I did:

- Start out on level surface with a cool engine.
- Remove expansion tank cap and top off coolant if necessary. Leave cap off.
- Start car. Let it idle. Monitor level in expansion tank. If it starts to boil up, etc., shutoff engine. This happens on some Asian models when you try to "air bleed" them. Didn't happen on my Benz.
- After about 15 mins., I saw coolant level rise up a bit. At that point, I turned on the heater to allow complete circulation. Let it idle another 15 mins. with heater on. Coolant rose just a bit more, but never bubbled or boiled out. I allowed car to idle for a total of 30 mins.
- I suspect the air was forced out as the coolant rose.

Maybe this will help your situation.

jsmith · #73 07-18-2002, 02:57 PM

alan,

okay, i understand what you meant, but are saying that when the aux fans are on and the engine is running, it doesn't cool down? also, i would think the cut out point should at least be below 100C. in the m104 engines 106C is when fans cuts in. i had a crazy overheating problem like yours more than 20 yrs ago with a mitsubishi four banger. when it was running normal, everything was fine but when it ran hotter it quickly went into an overheated state from which there was no recovering. my mechanic opened up the head for a look see (easy in those simpler designs) and saw that it had higher compression dome head pistons which was a late model changeover. the higher compression sorta explained the higher temps and to make a long story short i finally went and got an oversize radiator. that took care of that. my point is that your description of the overheating behaviour reminds me of that case and maybe your radiator is indeed plugged up and not providing sufficient cooling. BTW, remanufactured Behrs are available for about $125 - could save you some money. (resedaradiators.com)

#74 08-04-2002, 10:30 PM

DJNEWK2,

I am not trying to add more rain to your parade, but I've had a very similar problem with my off-topic 96 Lincoln Town Car (i didn't have this problem with my benzes...yet...). It began overheating a little bit at first, I was going nuts trying to figure out what was going on. I didn't overhead badly and only did it occasionally and was running like that for months until about 3 weeks ago. It was about 95 degrees outside and I was in traffic when temperature shot up to the max. I let it cool down, then restarted again and drove it back home - temps were OK. Then a day later - temp back to the max. I said enough, went driving to the shop - when I arrived, temps were close to the max, I suspected anything but headgasket (because I was checking both the coolant and the oil - no signs of any leakage were present), but on my final drive to the shop I noticed roughness on take off. In any case, after checking compression - it was the head gasket. So draw your own conclusions, just a story here to add to your deliberations, better safe than sorry (warped heads and all).

jsmith · #75 08-05-2002, 09:35 AM

head gasket failures on benz engines typically manifest as external oil leaks. by the time it reaches a point where there is loss of compression through there i would venture to say that the head is already warped from overheating. i had the well known head gasket failure on the m104 and i had neither power loss from compression, nor overheating - just a really annoying oil leak...