lets revisit overheating om603... - Page 2 - PeachParts Mercedes-Benz Forum

Brian Carlton · #16 04-15-2009, 07:59 PM

Quote:

Originally Posted by a2t

im gonna work up to the rad removal, try some easier stuff 1st but im probably headed that direction.

i know the fan clutch is toast, so i guess it will go like this :

1. check the 3 pin and aux fan operation
2. RR fan clutch (was gonna keep metal fan, unless you guys tell me 9 blade plastic is vastly superior?)
3. remove rad and clean it per brian.

dont worry, i wont just replace the rad, i will 1st try 2 clean it. $338 is worth a few hrs time. my exp with that sort of thing is i usually eff up the fins cleaning them. will let you know.

That's a good plan. See if you can get some temperature data at each interim step. My bet is on #3 for the maximum bang for the effort. We'll see if I'm right.

Ether · #17 04-15-2009, 10:21 PM

My newly acquired SDL runs warmer than I would like. Not as hot as Paul's but still too warm for my liking.

I have to flush out the green crap anyway so I thing I will take that opportunity to pull the rad and clean as Brian suggests.

Is Grainger a good source for the condenser cleaner? Any particular product that I should look for?

a2t · #18 04-24-2009, 10:27 PM

ditto on the condensor cleaner ques? NAPA? Joe I have a Grainger right near me by the airport at work and can go pick some up if you find they sell it.

Step 1 in my quest - I did a pressure check by removing overflow line to res and installing motul pressure bottle, found the stupid res cap leaking at 10 psi..

Replaced it w.1 from the benz dealer $9. Recheck and its all tight.

Dealer claims the 98-99 E300 fan clutch wont fit, others on here say it will. Im going to try it anyways. I will RR the rad and clean it at same time, since it prob has to come out anyways to get at it.

I tested the fan clutch by pressing some cardboard agasint it w/engine running at 110C. I was able to easily stop the fan. Guy at dealer said it shouldnt have stopped, fan clutch bad (already suspected that)

Also tested the 3 pin aux fan switch. Worked fine, seems that thing only controls super high speed at 128C (sheesh!). Wish the aux fan came on low speed with a/c comp, although on my car that would be 100% of time since my ACC is faulty and for some reason runs A/C all the time and cannot be switched off. Off button doesnt even work. Might wear out that pricey aux fan. Perhaps another console switch to manually turn it on and off. The wiring and # of switches are getting a bit ridiculous, this car is a NASA project already from WVO kit install.

Stay tuned ... parts arriving next week

Ether · #19 04-25-2009, 08:06 AM

Grainger does have the condenser cleaner. I bought a gallon yesterday at the one on Marietta street.

I plan on removing my radiator tomorrow and giving it a good bath.

BTW Paul, my CCU is jacked up as well and the compressor stays on 100% of the time. The aux fan does not come on so I've rigged it to run whenever the car is on. Will need to remedy that soon so I don't burn it up.

a2t · #20 04-25-2009, 09:00 AM

i thought my ccu was the only 1 that didnt shut off...hahhah. i have been dealing with it for 3 yrs. Too much AC is better than not enough AC. You can send it in for rebuild for few hundred, or buy new unit for twice that.

I was thinking about rigging in the aux fan too. Its $147, might be worth it even if it did wear out faster.

let me know how it goes on cleaning rad. ive got to go off to unicoi gap park today/tomorrow with my son camping so it will have to be next weekend for me.

dieseldiehard · #21 04-25-2009, 02:23 PM

Quote:

Originally Posted by a2t

(cut)
Dealer claims the 98-99 E300 fan clutch wont fit, others on here say it will. Im going to try it anyways. I will RR the rad and clean it at same time, since it prob has to come out anyways to get at it.

I tested the fan clutch by pressing some cardboard agasint it w/engine running at 110C. I was able to easily stop the fan. Guy at dealer said it shouldnt have stopped, fan clutch bad (already suspected that)

The 98-99 fan is plastic with more blades than the original metal one and only fits the 98-99 thermo clutch.
The dealer was just telling you what they see on their EPS.
I am not the only person using this combo on the '87 603 engine. The mounting bolts are different than on the original so you will need to order from a dealer.
One member saw improved cooling after going to the later version fan.
The thermo clutches do go bad and your test was conclusive. The dealer was right about that.

Bio300TDTdriver · #22 04-25-2009, 02:40 PM

Quote:

Originally Posted by dieseldiehard

The 98-99 fan is plastic with more blades than the original metal one and only fits the 98-99 thermo clutch.
The dealer was just telling you what they see on their EPS.
I am not the only person using this combo on the '87 603 engine. The mounting bolts are different than on the original so you will need to order from a dealer.
One member saw improved cooling after going to the later version fan.
The thermo clutches do go bad and your test was conclusive. The dealer was right about that.

His test was conclusive if he knows the clutch was receiving the correct temperature to make it activate. If the radiator happens to be blocked, and the clutch doesn't heat up, it won't activate.

JonL · #23 04-25-2009, 04:19 PM

Quote:

Originally Posted by Bio300TDTdriver

His test was conclusive if he knows the clutch was receiving the correct temperature to make it activate. If the radiator happens to be blocked, and the clutch doesn't heat up, it won't activate.

Good point!

a2t · #24 04-26-2009, 05:38 PM

But I can use the newer E300 98-99 fan clutch with the old metal fan, right? For sake of not spending too much $ Id like to stick with metal fan, it should do fine (if it fits the clutch)

I know the clutch wont see high temp if rad blocked but i shot the rad with IR gun best I could tell it wasnt blocked. To get rad out and clean, might as well replace fan clutch at same time, its got 286k on it.

I removed it couple years ago to RR water pump, I wonder if I didnt install it right (bolt tight). Will find out...

a2t · #25 04-26-2009, 05:42 PM

Quote:

Originally Posted by a2t

But I can use the newer E300 98-99 fan clutch with the old metal fan, right? For sake of not spending too much $ Id like to stick with metal fan, it should do fine (if it fits the clutch)

I know the clutch wont see high temp if rad blocked but i shot the rad with IR gun best I could tell it wasnt blocked. To get rad out and clean, might as well replace fan clutch at same time, its got 286k on it.

I removed it couple years ago to RR water pump, I wonder if I didnt install it right (bolt tight). Will find out...

Just completed 250 mile trip with new cap installed. System ran cooler but still hot. On hwy I could keep it 100-105C max, mostly 90-95C while moving. Going over unicoi gap, however it nearly maxed at 120C

That was 11am this morning, 75 degrees ambient. Its pretty steep climb for 15 min at low speed, all this seems to point to fan clutch. I was about to shut it down and let cool if it hit 120C but I crested the pass and as soon I started back down hill it dropped to 80C within a few min. I dont like that very much, Im sure the #14 head didnt either...

once i get this fixed I will test on the 9 mile climb up brasstown bald. if it can do that, it can do anything. no way id try it now, that would surely be the end.

Ether · #26 04-26-2009, 08:23 PM

I pulled the radiator and cleaned it thoroughly today with the commercial condenser coil cleaner. It was pretty dirty but I didn't see any major areas that were significantly blocking air flow. I gave the AC coils a good cleaning as well.

Bad news is that this didn't have any affect on my running temp. After refilling the system with Zerex I went for about a 10 mile drive and the temp quickly rose to just under 90 degrees. Under hard acceleration it will tickle 100.

I think the real culprit is the fan clutch. I took notice of it when I returned home and shut off the car and it continued to spin for a good 3 seconds. I suspected that was the problem but I figured I would give the cleaning a go first.

So, I'm curious about the 606 clutch option as well. What combination works? Do you have to use the 606 clutch and fan?

Brian Carlton · #27 04-26-2009, 10:17 PM

Quote:

Originally Posted by Ether

Bad news is that this didn't have any affect on my running temp. After refilling the system with Zerex I went for about a 10 mile drive and the temp quickly rose to just under 90 degrees. Under hard acceleration it will tickle 100.

Why do you believe this is a problem? The engine certainly doesn't care about a temperature of 100°C. In fact, depending on the gauge, that's about the point where the thermostat is fully open.

The point to get concerned is when the temperature climbs above 105°C. and that point will only signify that you should start looking for the problem. The engine will operate at 105°C. all day long and never give you a hint of trouble.

Many folks are overly concerned with this engine running at these temperatures. However, the problem with the engine is when that needle heads over 120°C. which typically occurs when the water pump goes south or when the engine is low on coolant.

a2t · #28 04-26-2009, 10:18 PM

Joe - heres what I have on the subject - http://www.peachparts.com/shopforum/showthread.php?p=1996319
post #22
south atlanta benz dealer disagrees though...

parts arriving here shortly, i will find out this week and let you know for sure

i cleaned my rad 2 yrs ago pretty well so i kinda doubt its that but i will try it anyways seeing how rad has to pretty much come out to do the clutch install. hopefully easier on your sdl than my 124

a2t · #29 04-26-2009, 10:22 PM

Quote:

Originally Posted by Brian Carlton

Why do you believe this is a problem? The engine certainly doesn't care about a temperature of 100°C. In fact, depending on the gauge, that's about the point where the thermostat is fully open.

The point to get concerned is when the temperature climbs above 105°C. and that point will only signify that you should start looking for the problem. The engine will operate at 105°C. all day long and never give you a hint of trouble.

Many folks are overly concerned with this engine running at these temperatures. However, the problem with the engine is when that needle heads over 120°C. which typically occurs when the water pump goes south or when the engine is low on coolant.

agree, but my 124 never ran over 100C 2 yrs ago. 105C wouldnt concern me all that much but we're still in the cold season here in ATL, wait a few months in ATL traffic, pavement temps over 125F are common. if its running 105C now ... and has a 14 head ... i'd be up at night too (unless I was planning on moving north)!

can anyone confirm or deny the test procedure for fan clutch i described earlier - sticking peice of cardboard agasint fan blades at idle with +100C coolant temp - should it just easily stop ?? I wouldnt try with anything other than metal fan, but a BMW mechanic suggested it to me to test fan clutch. he said it should keep spinning (and shred cardboard) at that temp.

Brian Carlton · #30 04-26-2009, 10:39 PM

Quote:

Originally Posted by a2t

agree, but my 124 never ran over 100C 2 yrs ago. 105C wouldnt concern me all that much but we're still in the cold season here in ATL, wait a few months in ATL traffic, pavement temps over 125F are common. if its running 105C now ... and has a 14 head ... i'd be up at night too (unless I was planning on moving north)!

You might expect a correlation between ambient temperature and the engine temperature, but, surprisingly it really doesn't exist.

The '86 will climb to 100°C. during a heavy uphill climb...........and that's at 50°F. ambients. In the dead of summer, with the ambient at 100°F., the same hill results in an engine temperature of 105°C.

Remember, the temperature on the gauge is not at all reliable. What you see as 100°C. might be 92°C. and the thermostat has not fully opened.