High Engine Temp! Need Help Asap Guys! - Page 2 - PeachParts Mercedes-Benz Forum

DJNEWK2 · #16 05-30-2002, 09:54 AM

Well it SEEMS that the viscous fan is alright and the radiator is still brand new.What I actually did was blast the heater last night and let the windows down and open the sunroof and the temp would go down. I guess the heater "trick" helped to lower the temp to just above 85 degrees until I got it back on the highway and could cut it off. I really hope that it isn't a head gasket (and so far no smoking nor water in the oil, etc). I'm going to check her out again at lunchtime with a short drive to see how she acts.At least she didn't have a crap load of coolant on the ground like yesterday. I'm thinking of changing out the thermostat, and also getting her a leakdown test for the compression, etc sometime soon. Anything else?

#17 05-30-2002, 10:29 AM

Haven't changed the thermostat yet??? It could be sticking causing the problem. I know it is not recommended - but for a test I would do it - take the thermostat out and see how the car performs. If the problem disappears---------. Fast easy and doesn't cost anything. Worth a try.

DJNEWK2 · #18 05-30-2002, 10:56 AM

Yea I'll probably end up changing the thermostat out anyway...My worry is that with all of the up and down of the temps, I will end up blowing a gasket (although the trusty MB dealership techs keep saying that its made to withstand 120+ temps with no problem until it surges way past the redline!). I don't care what they say, just because it MAY be able to withstand it, why even put it thru that constantly? Can't understand it myself but it was like they wanted me to just drive the hell out of her without even paying attention to the temps because it can ''TAKE IT'' so to speak. I know these are superbly crafted automobiles, but I like to pamper my baby as much as possible to sustain a long (er) lifespan.

Anyone besides Mike and I feel that the 560 runs normally at a steady 80-85 degrees tops or are there other 560 owners that run at 100+ constantly?

Alan

greenacres2 · #19 05-30-2002, 11:01 AM

I'm always at 80-84 now, ran hotter before reconnecting the overflow hose which for some reason seemed complete the pressurized system. Ran 85-100 prior.

#20 05-30-2002, 11:07 AM

I talked to Mercedes Canada Technical Help last month and they guy told me that as long as the temp DOES NOT EXCEED 120C gaskets and head should be fine. He said you definately do not want it to climb to 125C or serious damage could result. Hey Earl - what exactly did you do with the overflow hose that reduced the temp?

DJNEWK2 · #21 05-30-2002, 11:54 AM

I'm interested in what you did also...Moe, what temp is your 560 running most of the time? I'm convinced that they should'nt be above 100 degrees but even with the thermostat not even supposed to open until it hits like 87, its kinda crazy that it was reading 80-82. Go figure...I wonder what you did to the hose because I'm going to my MB parts supplier to pick up a new expansion tank at lunchtime since he's just 15 min away and has it in stock and may pick up another hose to boot. I figure if it doesn't work, I'll take it back but what the heck.

#22 05-30-2002, 12:36 PM

With all my overheat problems, I am down two last resorts- coolant temp. sensor or Freon pressure sensor. Our temps up here are only about 60-70F right now so my 560 runs OK at about 85-90C all the time. Have not had to use AC yet. When temp goes up to 80-90F then I will see if it still climbs to 110C and will use IR non-contact thermometer on the block to verify actual temp. Be patient - I will solve my problem - or die trying. Hey Greenacres2 - still waiting to hear what you did with your overflow hose - don't forget us!!

PS - the old 1930 Chevy has a huge Rad and NO thermostat(were not invented then)and runs well -also no oil filter - just a splash system like a lawnmower! Technology - go figure!

DJNEWK2 · #23 05-30-2002, 01:26 PM

Just got back from picking up my new expansion tank and of course she ran at 82 steady on the way there but on the way back, she shot up past 100 again (which the aux fan kicked in at that point) and when I parked, I saw coolant again coming from the cap area...One guy from another supply center says I need a kit to install it but the guy I got it from says otherwise.I will have to take my sensor out and put it into the new tank though. I guess this will be an ongoing problem until I can pinpoint what the deal is with this coolant temp issue.

greenacres2 · #24 05-30-2002, 01:57 PM

Runs from expansion tank to overfow reservior in right fender well. Was broken off (old, brittle) at expansion tank. Removed right front tire and cowling from wheel well to expose overflow reservior. Replaced hose with one from FastLane. There was no sign of leakage prior, and I only did it to clean up the engine bay but the operating temp has not gone above 84 since, and we've had weather up to 90f a few times. Did the hose in early march and that's the only thing I did at that time or since to the cooling system. I replaced the thermostat in December, and I'm pretty sure it's an 80c t-stat.

It doesn't look like the overflow would come into play unless the coolant gets too hot, but I would idle at up to 100c prior. Only thing I can figure is that the overflow helps with pressurizing the system and closes the loop. Half hour job tops, and that's for a novice DIYer.

DJNEWK2 · #25 05-30-2002, 02:50 PM

Looks like I'll be trying to switch out my level sensor to go into the new expansion tank.Does anyone know how difficult this is? I heard from the guy I bought it from that I'll probably break it trying to get it out but its possible. I wanted to just get a new one with it but he had none in stock. Also, how difficult/how much time does it take (approx) to change out the thermostat and water pump? I'm thinking of doing the water pump soon for the heck of it too.

Alan

#26 05-30-2002, 03:11 PM

Figure on 3 hours for the water pump - unless you have a leak and have to do it over again. When I changed mine the gasket weeped - took it out again and applied a LIGHT coating of silicone to gasket and re-installed - no problem

mplafleur · #27 05-30-2002, 04:04 PM

I lightly went though the multitude of replies.

I put my money on an air bubble in the system that can't be purged. There is a plug on top of the block back by the firewall used for filling the coolant passages in the block. Take the plug off and slowly fill with coolant. If there is air back there, you will not get coolant flow, even with the water pump turning. Check this before you replace the pump.

dnthomas · #28 05-30-2002, 11:45 PM

Have only had my 560SEL for a short time but done lots of highway driving and temps for me remain steady at 80-85 degrees. This of course has change in heavy stop and go traffic in this hot Mississippi weather and then went up to 100 or so and immediately back down when back at normal highway driving. In town, remains 80-85 even on very hot days.

omegabenz · #29 05-31-2002, 05:04 AM

The coolant level sensor is easy if you have the right pliers. The ones that push clips apart.

My brothers 560 kept fluctuating on the temperature. We thought it was a bubble, but one of the hoses had a pinhole in it. We have a coolant pressurizer, and we pumped up the system and coolant shot out and we found the hose.

If the coolant tank, cap, radiator, and viscous coupling on the fan are new/working properly, then I would look at the thermostat. Since you have been through six gallons of coolant, I dont think that you have air bubbles in the system.

See if all your connections on the coolant tank are secure.

Try the thermostat next.

Good luck,

Austin

mplafleur · #30 05-31-2002, 08:13 AM

Could still have the bubble and go through gallons of coolant if it boils off because it is not circulating. It's the same as if the pump is shot.

Tell me if I'm wrong.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode