300te 4matic smoking exhaust

[pde2000]

I've been considering replacing the valve stem seals on my 89 300te because of the copious smoke when up to temperature, as i pull away. The problem was worse this summer than it had ever been and was getting embarrasing and making town driving impossible. However I took the car on a long drive (holiday) and by the end it had stopped smoking. also the oil light kept coming on but the dipstick showed just within minimum. i've been regularly topping up the oil, which it uses a lot of - obviously. Now i realise there may be another problem - maybe a breather in the sump is blocked. Does anyone have experience of this? My dad had a volvo 245 which had a breather problem and he recons i'd be wasting my money having the valve stem seals replaced (car valued at £500ish), but what should i do?

Since i got the car 5 years ago its had new exhaust, front cv gaitor (4matic dont work but still gotta have its driveshafts intact), replace distributor (moisture was accumulating), added an electric cooling fan and replaced the viscous clutch, and wasted £460 on a service at Romford MB where I was given worst treatment - i dont even want to talk about it. Apparently they're under new management but I've found lakeside very usable and they're not 'stuck up' if you know what i mean.

I'm balancing costs as at the moment i'm being squeezed by the ex (a common feeling I'm sure). Over the year my running costs are low enough for the distances I drive, but to throw any serious money at an already worn out car just doesn't make sense. If i can solve problem cheaply i'd be over the moon - you guys helped a couple of years back when the engine kept dying due to tracking in the distributor.

 

[Tomandjo2]

Valve stem seals more likely to cause smoke when first started as they are supposed to prevent oil running down to the valve stem onto the piston which will happen when engine is off (hence lots of snoke when you start).

If you are suffering increased crank case preasure and smoke when warmed up more likely to be worn rings.

The value of your car is a consideration but also how much are you going to spend on a replacement car and how much do you like your current car?

Tom

 

[Dieselman]

Firstly check the breather system is clear. A simple check it to pull the pipes off the air intake and see if it's breathing properly.

If it's breathing heavily then the rings are probably worn out.

If it's blocked check and clean the PCV valve.

It could be the valve stem seals, check by going down a hill and changing the gearbox down a gear to create engine braking.
When at the bottom apply some power. If the cars behind disappear then the valve guides seals are gone.

As far as the front driveshafs go jsut remove them.
This will give two benfits, one the MOT examiner won't be able to fail them and two, there will be less drag due to the front diff not turning.

 

[pde2000]

Thanks for your advice - I'm sure you're right about the rings being worn. There's no smoke on start or that downhill braking, but also the breather to the air filter seriously blows, but that's off the rocker box. I think I'll just run it with minimum oil from now on, and put a little bit in at a time to keep it topped up as that seems to be preventing the smoking. The cost of a rebuild (wouldn't be much less for just the rings replaced) puts it outside of my financial means and I dont think i could do it myself.

I didnt know you could get away with removing the front drive shafts - maybe somebody would buy them off me Also flog the rest of the 4matic bits - worth something to a real 4matic enthusiast?

Also whats a PCV valve - not sure ive got one.

 

[Ben's Mercedes]

It does sound like stem seals. However, consider the smokey problem I had on my 300te 4matic. Transmission oil leaking from the faulty transfer case onto the exhaust pipe causing a huge smoke screen out the back. I noticed you said your 4matic doesn't work. Neither did mine.