white smoke from exhaust 300 se 1990

[karlos77]

hello have a 1990 300 se automatic which when i stopped at a round about started pluming white smoke from the exhaust. is this the head gasket or is there another fault on these which it could be??
please help!!!:-( :-( :-(

 

[MR DAMAS]

In my experience these engines have very few problems with the head gaskets although i'm not saying they never go. I would need some more info to give you a proper answer.

 

[daveenty]

If it's clouds of white smoke, check the brake servo out.

Sounds stupid, but if the diaphragm's torn it can suck brake fluid into the inlet, giving the symptoms you describe.

 

[shirubaby]

valve stem seals, possibly??. Search on the forums for it. It is also possible to replace them without having to take the head off.

One way to check: take the spark plugs out and see of they are oily or covered in black cruddy stuff (not fine carbon deposites)
A puff of white smoke when starting the car in the morning or booting it from standstill.

This forum is great for tips on diagnosign valve stem seals.

BUT also remember the exhaust on these mercs are big and it can be simply be moisture in it being evaporated off.

 

[karlos77]

owner

hello a bit more info.
the car has been fine with absoloutly no faults, until i stopped at the round about, this is when i noticed the smoke. when i got home with the car in neutral it still smoked only at a lesser rate then when you press the accelerator big plumes of white smoke again. also today when i turned on the ignition the coolant light is on, it has lost fluid, i did not want to take it for a run to see if everything was ok.
oh yes and another thing the other day when all this happened i noticed the car car was kind of juddering as if it was going to stall but not quite when i depress the accelerator but after aa while it would be ok!!!
thanx on all your anticipated help!!!!

 

[Blobcat]

Sounds like head gasket, a compression test should show this up.

 

[shirubaby]

if the 300se has a 3 litre 6-cylinder engine like my 300ce... then it's not that difficult to replace the head gasket.

Need two blokes to lift the head off

 

[karlos77]

thanx

thankyou for your info will do pressure test!!!!:smile: :smile: :smile:

 

[karlos77]

it is the 3 ltr 6 cyl, can you tell me will it be necessary to skim the head when replacing the head gasket???

 

[Blobcat]

It depends, if it has corroded due to the water or twisted due to overheating then yes the head will require a skimming

 

[oigle]

Just another possibility - Never seen a blown head gasket causing white smoke - steam sure, but not white smoke. As you have lost coolant, a head gasket or something else in the cooling system may have a problem for sure, but the only time I have seen WHITE smoke from a car was when auto transmission fluid was being sucked in to the manifold via a vacuum tube - makes for huge clouds of white smoke. Be an idea to check your auto trans fluid level. The oil going in in that quantity could also be responsible for the poor running.

 

[karlos77]

does anyone have a repair manual for this car so i can have a look at what is involved in doing this job before i attempt it???
please

 

[shirubaby]

Just another possibility - Never seen a blown head gasket causing white smoke - steam sure, but not white smoke. As you have lost coolant, a head gasket or something else in the cooling system may have a problem for sure, but the only time I have seen WHITE smoke from a car was when auto transmission fluid was being sucked in to the manifold via a vacuum tube - makes for huge clouds of white smoke. Be an idea to check your auto trans fluid level. The oil going in in that quantity could also be responsible for the poor running.

he's gotta point there, remembered this on another thread.

 

[shirubaby]

does anyone have a repair manual for this car so i can have a look at what is involved in doing this job before i attempt it???
please

dont think there is a haynes manual for this car. MIght want to read the w124e-class haynes manual...might be similar stuff. Thus you can get an idea. Bigger engine bay in the SE means things will be easier for you (a bit).

Taking the head can be as simple as taking eveything apart....and putting it back together. The most difficult bit will be removing the head itself (as it will be pretty stuck after so many years).

 

[TimN]

I would expect smoke that was generated with oil as it's base to be dark with a blue hue to it altough I would admit to spilling hydraulic fluid on the exhaust manifold which the gave off copious amounts of white smoke.

Water is a byproduct of the combustion process but not in such great amounts as you are experiencing.

To determine whether you need a skim obtain a draughtsman's steel straight edge. Once the head is off place the straight edge across diagonals. Check to see it it rocks or you can get a feeler gauge under it. Then consult your local friendly engine reconditioners. I'm sure the following will help.
Power Units (Hatfield)
16, Bury Rd, Hatfield, Hertfordshire AL10 8BJ
Tel: 01707 264310

If you are having rapid coolant loss you can rig it so that you can determine the level at which the coolant stabilises. From that point you can determine the likely point of failure by looking at what other functions lie at that level.

 

[karlos77]

hi guys head is off and there was a fracture in the main head gasket so i think problem is solved apart from checking for twist or bend in cyl. head, but theres no rush for this as i dont get the new head bolts for another three days

 

[karlos77]

just to let you know the gasket was split between pot two and thewater jacket between pot 1 and 2 on the exhaust side !!!

 

[shirubaby]

i dont get the new head bolts for another three days

Read the leaflet that comes with the headbolts carefully. Not all of the different manufacturer types torque-on the same way.

Mine needed to be loosened and then re-torqued....

HOwever, well done in getting the head off...not too bad eh?

Now that it's off, you might as well replace the valve stem seals.

And have a look at the top of the cylinder bore...you might not even find a pronounced ridge...

AND have a look at the cylinder bore inner surface....you may find the original honing pattern...still present....if you look carefully.

All this indicates mimal wear of the engine.

 

[karlos77]

done and back together was working but now i have an electrical fault, i think it may be a little sensor at the back right of the engine, it has a four pin plug but now i have looked at it the socket doesnt have a flat on one side like the plug so i may of plugged this in incorrectly as it will plug in four different ways can anyone help?????

 

[karlos77]

the car was running then died on the way home i cannot start the engine now it turns over but wont ignite and my petrol light is constantly on and electrics are dioing strange things