1994 C280 Overheating (HELP!!!)

[stargazer474]

HI All,,

I need some help ,, I own a 1994 C280 and have been having some problems with it over heating and so forth , my temp gauge in the insrtument cluster hasnt worked sence i bought the car , well not untill it over heated one day , it has allways stayed at 40 and hasnt ever went up or down , no movement at all !! well when it over heated it jumped up to 90 but i know for a fact the engine was much hotter then 90, i bought a scan tool and it is telling me that the ECT sensor need to be replaced which is no problem i will be doing that soon , but now i have read somewheres that there are 2 temp sensors one for the temp gauge in the instrument cluster and one that works the 2 little radiator fans ,, is this true , because as far as i know the 2 little fans that are in front of the radiator have'nt ever worked either sence i bought the car,, the car has a oil leak which we believe it from the oil pan gasket, and it seems to go threw coolant quickly i have to fill it up at least once a week with new coolant but i believe that is from it over heating and evaporating also ,, any ideas or help for me????????? please

stargazer

[martattack]

There's actually three temp sensors:

One for the Gauge, one for the ECU, and the last one is for the A/C unit which controls the fans. If your front fans are not turning on when it gets really hot, that is a problem. Could possibly be the fuse, fan relays, temp sensor or even the A/C control unit.

I'd start by checking fuses.

[rollinrealbig]

are you sure its not a blown Headgasket ... because that can eat up coolent fast, and also be the answer to your oil leak!

this is sort of a common thing on C280's ive noticed. never heard of this happening on a C220/230

[stargazer474]

Thanks for the replys , wow i didnt know there was three temp sensors... by the way yes i am a famale lol and yes i know a little about cars ( comes from my dad growing up) ,,, anyways i will deff have to get on checkin out the fuses because i know there are a couple of them that are blown and i also need the combo relay for the turn signals and the wipers , that relay works a number of things , and just about everything it works is messed up or not working properly on the car, a while back i had a bunch of problems with my head lights not wantin to turn off and my interior lights wanting to stay on and i changed the headlight switch and it fixed all those problems so , so far the problems i have been having have been minor ones that can be fixed fairly easy, ok now for a probably stupid question , Is the Valve Cover Gasket and the Head Cover Gasket the same thing or are they two diff gaskets? because when we were looking for oils leaks around the valve cover gasket we didnt see any oil at all comming from there , but when changing the oil we seen about 3 to 4 diff spots on the oil pan that seem to be leaking and one of the spots is a type of bolt that is on the side of the oil pan , not the oil drain plug but it is a diff bolt and you can see that the oil is dripping and draining from around the bolt like maybe a rubber (O) ring around it or something needs replaced , but if i go threw the trouble of dropping the oil pan then i will just probably have it replaced while its off the car, so far i have not tryed replacing any of the gaskets as of yet because we are still trying to narrow down where exactly the oil leak is comming from, i have replaced the thermostat thinking maybe that was the reason for the over heating but it was not , it has not over heated as bad as it did before i replaced the thermostat but it still gets way to hot, >>>>> By the way anybody know anyone who lives close to Mentor Ohio and is a decently prices Mechanic ?? LoL i really need one,,

Stargazer

[rollinrealbig]

cool a female 202er, second one ive run into this month! LoL

the valve cover gasket looks like this -



and the Headgasket -

http://i4.ebayimg.com/05/i/06/f0/b5/b5_1.JPG

the headgasket is not so cheap to replace, so be careful!

the valve cover gasket is not a big deal at all, as long as the oil doesnt find its way into the spark plug area.

[Vodka G]

you probably just need a new oil pan gasket (judging from how you described it)

do you see your tail pipe smoking??

are your fans working (both the large one and the two smaller aux fans)

what about coolant leak??? and pressure??? i know that the gasket/seal between the water pump and the engine tends to leak (i had that happen to my old w202 twice)

[stargazer474]

Nope No Tail Pipe Smoking. ,

as for the Fans

The bigger one Works
but i dont think the 2 small ones are working
i have never heard them kick on at anytime ,

someone told me to try to take a wire and jump them off the battery to see if the little fans will work but i dont know if thats a good idea or not.

and as for a coolant leak i am not sure if there is one or not. everytime i see something on the ground from where it has leaked it is oil.

[dshenberger]

If you need to fill the coolant every week how can you NOT have a leak? How many miles do you have on it? You don't need a mechanic! These guys know more than most shops!

[jnolte]

did you check the fuse for the fans? they should kick in if the car gets too hot

[1995c280]

if you dont want to jump power to the fans, just unplugg the coolant temp sensor. the fans will turn on almost imediately if they are working properly then plug the sensor back in and the fans will go off!!!!!!!!!! but like jnolte said, check the fuse first and then move onto this...

Jason

[Vodka G]

Originally posted by dshenberger
If you need to fill the coolant every week how can you NOT have a leak?

true

and it really sounds like you blew a head gasket...judging from

1. you are going losing coolant every week....without a leak.....and when you are losing that much coolant is pretty easy to spot......

2. the coolant gotta be 'lost' somewhere else......and the only other place that i can think of is through 'burning' which means that your head gasket is toasted

3. the overheating is also a sign of blown head gasket

another thing to check is look for oil trace in your coolant......and if you do see oil in your coolandt then its 99% positive on blown head gasket


pretty costly to repair

how many miles???

[stargazer474]

Hmmm interesting ideas ,,

If it was a blown headgasket would i loose compression?

and i did not say i didnt have a collant leak i said if i have one i do not know where it was leaking from. i do know when it gets hot that the container that the coolant goes into will hiss and spew coolant out of it from the sides.

and as for something being in the coolant i have a white substance floating on top of the coolant when i open to look in it, i dont know if thats cause from the coolant getting to hot and breaking down to quick or if its from something else.

and as for the milage it has 123,000 on it, it hasnt overheated in a while now and still has pleanty of get up and go to it , like i said when it overheated that one time i let it set for about 45 minutes and cool down and added water to it and started it up and it has ran like it never overheated every sence ,

stargazer

[jnolte]

do you get alot of white smoke in your exhuast?

[1995c280]

stargazer, if you need the combo relay still, i have one that's brand new. check your PM's. i sent a message there. make me an offer!

Jason

[Vodka G]

Originally posted by stargazer474

and as for something being in the coolant i have a white substance floating on top of the coolant when i open to look in it,
stargazer

that's also one of the symptom of a blown head gasket....white bubbling coolant...aka air leak into the cooling system

cooling system are suppose to be sealed (that's how they can hold pressure) and if you have a blown gasket the system is no longer 'sealed' and that's why you see those white bubbles

basically if you see anything else beside normal 'coolant' in the cooling system....you are in trouble......

judging from the description (without actually looking at the car) i am pretty sure is a toasted head gasket

[martattack]

The white substance is likely oil sludge. This means your coolant and oil are meeting up. Primary cause, as VodkaG stated.. blown head gasket.

[stargazer474]

Thanks Again for all of the responses ,

I have no Smoke Comming out of my tail pipe.


Ahhhhh ok now i feel like going and pulling my hair out somewheres , LoL ,

I dont want it to be a blown head gasket!!!!! , LoL not like have much of a choice if thats what it is huh ,,

boy do i wish i had some of you all living closer to me i would bring it to ya and have ya look at it for me . LoL i know its hard to give suggestions over the interent when ya cant acutally see the dang car,

I allways thought if ya had a blown head gasket you would lose compression though ,

Stargazer

[martattack]

Almost all the time you do lose compression with a blown headgasket . Have you run a compression test or a leak down test on it? If you have and all the cylinders check out, it could be a very bad thing (ie cracked/warped head) if the coolant and oil are still mixing.

Martin

[stargazer474]

No i have not done a compression test on anything yet i am just going by how the car runs ,

it runs like there is nothing wrong with it at all ,

and if i have to put extra collant in it or oil once i do it doesnt over heat , unless your driving it for a long while then u smell oil burning , but i am thinking its cause the oil is dripping on the manifold ,

I just really dont know anymore i am thinking of takein it to the garage thats down the road for me and seeing how much it will cost just to have them check it out and see whats deff wrong with it

[Vodka G]

i know a full head gasket repair should cost around $1500-$2000 with parts and labor

[rollinrealbig]

so 123,000 miles

1994 C280

losing coolent

oil leak

white substance in coolent


its all pointing to blown HG, and check your fans - if they didnt turn on that may be why your gasket blew ???

and I dont know if theres a differnace in power (as I havnt blown any headgaskets lately) but maybe yours was burnt a while ago and now just got burnt more to where you are having these issues.

this is so common on C280's for some reason - thats one of the reasons i ended up with a c230

[Vodka G]

well my car had 203,000 miles when i sold it and the HG was still gud :-)