300e still runs hot - PeachParts Mercedes-Benz Forum

lee polowczuk · #1 08-25-2007, 06:44 PM

I just replaced the fan clutch, thermostat, water pump and cap on the 300e.

No leaks which is good. I just put water in it to make sure it wasn't leaking.

Car gets up to 106-110 and the high aux fan is kicking on... also kicks on at low.

I am fairly certain that the aux water pump isn't working, but it is my understanding that has nothing to do with engine temp.

radiator seems fine... everything else seems fine... it wasn't even that hot here today.

I can put in the Zerex next after the car cools down and I can drain the water... but I don't know if this will help with cooling that much.

I will say this.... after having the car all torn down... it didn't seem like it took that much water to refill it... I guess the block was virtually full. I'll have to check that out when it cools... i'll drain from the block and the radiator..

lee polowczuk · #2 08-25-2007, 07:39 PM

May have answered my own question.

It took 3 more quarts... this time I added the Zerex... still have another quart of Zerex, will see if it needs more after it cools down.

Still, I will probably drain a bit off from the block side, and add the remainder of the Zerex. May get some Wetter Water.

Car still runs a bit hot, under 100... probably in the 93-95 range.

brewtoo · #3 08-25-2007, 11:06 PM

Does your car have two aux fans?

I know on the ones that have two (and probably the ones that have one), they accumulate an incredible amount of crud down in the bottom of the fan shroud in front of the condenser.

On my cars it was blocking about the lower third.

saumil · #4 08-25-2007, 11:25 PM

Aux fan running in the right direction ? The air should go in the engine compartment from the outside. See if a small piece of newspaper gets sucked in or blown away by the fan, if sucked in, direction is o.k.

lee polowczuk · #5 08-26-2007, 09:44 AM

Aux fan is ok... just one..

All the debris cleaned out..

I am going to drain a bit of water from the block, and put the remaining coolant in... with some Wetter Water..

I think we will be fine....

For those who have to do a water pump: Either get the Snap On 13mm wobble.... or

here's what I did... I had a 1/4 inch drive 6" wobble extension. I went to Sears and got a 1/4" drive 13mm socket for less than 3 dollars. That got it.

When I re-assembled, I did the tough bolt first, starting it by hand... doing that much of the way... and then actually used a 13mm closed end wrench to tighten. I could have used the wobble extension, but the socket fell under the car and I was too tired to go after it.

This took me 6.5 hours.. I wasted too much time trying to get the bolt out with 3/8" drive like some have. I also had to go to Sears.

I think I could do it in 3.5 hours the next time.

brewtoo · #6 08-26-2007, 10:43 AM

Yes, I got that 13mm sears tool also. The second one did not break.

Rick Hall · #7 08-27-2007, 01:37 PM

Reading these posts, quick question. I have the radiator out of my 91 124 at the moment. I noticed that there does seem to be soem accumulation of "crud" at the bottom of my evaporator coils. Noticed in this post that someone stated that they cleaned these out. What is the best way to get this done? Will start on cleaning mine soon and thought air first @ 100 PSI and then hard water stream from inside. Will this "gat er done"?

lee polowczuk · #8 08-27-2007, 02:33 PM

I would just hose it down.

There is also a commercial coil cleaner that you can get at a plumbing or a/c type shop.

Stuff is non-corrosive.. i have only used it on my home a/c.. car has never been that dirty.

mctwin2kman · #9 08-27-2007, 02:36 PM

You also have to make sure you Burp all the air from the coolant system. Air pockets do not cool too well. LOL

Also is your clutch fan working properly? If the clutch does not engage properly then of course it will cause the aux fan to turn on. Also how new/old is that radiator, are there any hot/cold spots in it?

brewtoo · #10 08-27-2007, 04:01 PM

Quote:

Originally Posted by Rick Hall

Reading these posts, quick question. I have the radiator out of my 91 124 at the moment. I noticed that there does seem to be soem accumulation of "crud" at the bottom of my evaporator coils. Noticed in this post that someone stated that they cleaned these out. What is the best way to get this done? Will start on cleaning mine soon and thought air first @ 100 PSI and then hard water stream from inside. Will this "gat er done"?

If you are asking about the crud in the bottom of the aux fan shroud in front of the condenser...no, you will have no success trying to wash it out from behind. You will have to remove the shroud.

lee polowczuk · #11 08-27-2007, 05:12 PM

I think we about have it right.

Added the other quart of coolant and a bottle of Wetter Water. I don't know why I get the Wetter Water, just do..

Anyway.... we are in the mid 80's to 90 range. At least that's what my son reports to me today.

We also only have 90 degree temps today... came off off a couple of weeks of upper 90's to 105.

I am sure the radiator could stand to be updated... it's not original, and does have the reinforced collar... but it does appear to be on the older side.

I am lucky he didn't blow a head gasket last week. Car runs as good as ever, especially with the new motor mounts... what a difference

richard28 · #12 08-27-2007, 10:25 PM

Lee, have you made sure you have the updated fan and fan clutch? In my 1988 300ce I replaced the original versions and the temp needle no longer runs up to 110 degrees within minutes; now it stays below 100 and I have stopped worrying about non-highway driving. What a relief.

david s poole · #13 08-28-2007, 09:50 AM

original fan blade was white or cream updated to black with extra blade.

lee polowczuk · #14 08-28-2007, 02:35 PM

hmmm... don't think we have the updated one.... we will monitor the engine...

he said it barely got past the 80 degree mark today... once again the ambient was only in the upper 80's --15 degrees cooler than recent temps