Heat problem and coolant issue - PeachParts Mercedes-Benz Forum

D&W · #1 12-12-2010, 07:25 PM

So I've had the car for about 9 months now. (1968 w108 280se Straight 6)

I check the oil every week. Coolant probably once a month.

It was always fine, I topped it up a little bit after I had it for about 6 months.

Car was serviced 3 weeks ago and all new coolant was put in.

Yesterday I noticed on my way home it was getting hot while stopped for about 1 minute at a red light. It never heats up that quickly. Cooled slightly while driving. Got home and thought it was a bit strange

Checked the coolant before I went for a drive today and couldn't see ANY coolant in the radiator!!! (haven't driven it since just took these pics and posted straight away)

Here is a pic from in there... the underside of the radiator cap was clean as a whistle but those small white bits in there scare me...

The car never got to the red on temp gauge but came close. I did notice some water drops coming out the exhaust yesterday while it was cold out,

I have a bottle of coolant in the trunk I can throw in but trying to work out if I should try and drive it 15 miles to the mechanic or have it towed on my AAA card? Definitely don't want to risk anything

Any advise would be appreciated! I'm leaving for australia on thursday so need to resolve this ASAP!

cheers in advance

JeffreyNMemphis · #2 12-12-2010, 08:04 PM

If you don't see an obvious coolant leak, check your oil dipstick and see if the coolant is going into the engine.

D&W · #3 12-12-2010, 09:05 PM

There seems to be a little fluid on the ground. Here is a pic of the oil dipstick. Seems quite normal to me

Car was running with a miss yesterday it seemed too, it wasn't idling as smooth, which was not there after the service 3 weeks ago

280EZRider · #4 12-13-2010, 02:47 PM

If you don't see any leaks, I would check the end of the radiator overflow tube for coolant exiting (cooling system need to be full) after running. It's common for old radiator caps to lose their spring pressure and open at a lower-than-usual pressure, allowing coolant to escape.

JeffreyNMemphis · #5 12-13-2010, 02:55 PM

Quote:

Originally Posted by 280EZRider

.... allowing coolant to escape.

Very good point...

Stretch · #6 12-13-2010, 03:32 PM

The condition of your radiator doesn't look too scary to me - I guess after the coolant was changed at the workshop the car wasn't topped up properly. Did you by any chance change the heater controls? Sometimes air gets trapped during a coolant change.

Even so to check if the cap is leaking - tighten it properly as you normally do - and then wrap boll roll / toilet roll / loo roll => Oh you're Australian is it gonna be dunny paper or something? Anyway wrap some of this around the cap - if it leaks you'll get wrinkled paper - if not your car will look as daft as you do when you cut yourself shaving!

Good luck - keep us posted.

D&W · #7 12-13-2010, 06:51 PM

Nice one guys, thanks for the tips...

I called my mechanic. Tonight I'm going to fill it up on a hill, with cap loosened, warm it up then tighten cap, apparently that can help push out air caught in the system

I'll keep an eye out to see if there is any leaks underneath after topping up then take it for a quick drive and see how its looking afterwards.

I'm taking it down the mechanic tomorrow anyway, if there is anything weird still going on he can sort it out and ill prob get my valves sorted too as they need doing. oh and my cold start valve

thanks for all the advise!

meltedpanda · #8 12-13-2010, 07:54 PM

look under the oil fill cap for bubbles, frothing just to make sure you do not have a head gasket leak.
I had an old chevy once that showed no signs of leak into oil but in fact had a block crack that was the cause of the fluid loss.
OTOH not "burping the car properly could also be the cause as in not enough fill...
Good luck, let us know

Michael C · #9 12-13-2010, 07:55 PM

Make sure your heater valve is open as well when you fill and run it. (Run your heater) Get all of that air out.

Michael

D&W · #10 12-14-2010, 01:59 PM

Filled it up with about 1.5 quarts of coolant and 1.5 quarts of distilled water this morning, parked on hill, ran for 15 mintues at idle with heater on (blowing warm)

No leaks under car, no smoke out exhaust (5 mins of condensation only)

Drove 40 minutes in traffic, got to about 195 stopped at lights, cooled while cruising

No loss after driving, coolant was at same level

Mechanic will pressure test system, check thermostat, temp switch and check over it all in general... see what happens

meltedpanda · #11 12-14-2010, 03:09 PM

let us know, these mysteries are always interesting

D&W · #12 12-14-2010, 03:47 PM

mechanic is not sure why it lost coolant, he recalls it was topped up properly when they did the coolant 3 weeks ago.

pressure is fine, system looks in good shape.

he is having a look into the radiator to see if it needs to be replaced/recored. doesnt explain the missing coolant abut might help control the temp rising to 210 every so often in traffic (which it's been doing last few months)

he thinks it could also be the water pump not working efficiently.

should hear from him again later today

JeffreyNMemphis · #13 12-14-2010, 04:23 PM

I bought a new water pump for about $90.00. I also installed a new thermostat. My temperature generally stays at 180 degrees even during the blazing hot Houston summer.

Stretch · #14 12-15-2010, 04:55 AM

Quote:

Originally Posted by D&W

mechanic is not sure why it lost coolant, he recalls it was topped up properly when they did the coolant 3 weeks ago.

pressure is fine, system looks in good shape.

he is having a look into the radiator to see if it needs to be replaced/recored. doesnt explain the missing coolant abut might help control the temp rising to 210 every so often in traffic (which it's been doing last few months)

he thinks it could also be the water pump not working efficiently.

should hear from him again later today

If I were you I'd wait for a bit and see how this problem pans out. I admire the attitude you have towards the maintenance of your car - but I think you could end up paying money for a simple mistake made by the mechanic. If there is a leak - it will leak again - then it is worth spending what ever it takes to get it fixed. Until then just give your mechanic a bottle of wine for Christmas (if you must) instead of another big chunk towards his speed boat.

mak · #15 12-15-2010, 08:33 AM

Quote:

Originally Posted by 280EZRider

If you don't see any leaks, I would check the end of the radiator overflow tube for coolant exiting (cooling system need to be full) after running. It's common for old radiator caps to lose their spring pressure and open at a lower-than-usual pressure, allowing coolant to escape.

If checked and all correct i asume it is a old radiator cap . Likely the pressure valve inside did not close correctly due to rust, ageing etc.

mak