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Big Seafoam OOPS, 79 300TD

2037 Views 13 Replies 4 Participants Last post by  reinventthewheel
Ok, so my last car was a gas VW Jetta and when I got it, it had an incredibly dirty intake manifold. I did a few seafoam treatments through the vacuum lines and it worked miracles.

I just got a '79 300td (non-turbo) and there's been a lot of blow-by. The air filter and housing is full of dark oil, and the car smokes much more than it should.
My thought was that since I was dealing with a similar problem, I would turn to a similar solution. I sucked a half a can of seafoam through the thin vacuum line coming off of the thick one that leads to the brake booster.

Since the big cloud of smoke didn't come out afterwards I just started to look up Seafoam treatments on these vehicles and found all this scary stuff about hydro-lock. Yikes.

I've only driven about 1/2 mile since doing the treatment, but I'm supposed to be driving almost 300 miles tomorrow (hence the desire to clean out the intake before getting on the road).
SO! Did I fuck things up? What do I do to fix it?
Also, how can I clean out the intake manifold? Will seafoam in the fuel do the trick?

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So is my engine gonna be ok? Do I need to do anything to get the seafoam out?

Or is it just going through the vacuum pump and into the intake and probably not making it into the crankcase?
There was some seafoam dripping from a point at the back of the air box.

The oil was all over the air filter, are you saying that's ok?
Blow the oil cap off? Never heard of such a phenomenon.
Was out of town for a little bit.
Thanks for the info.

There is quite a bit of blowby. It will rattle the cap if I loosen it.
The oil was extremely filthy when I got this car, and was immediately black right after its first oil change. It also smokes a bit while idling.
I plan on taking it to someone with more experience for an engine check, but I'd like to do what I can to remove the carbon and lessen the smoke and blowby before doing that, though.
I should say:

My current plan is to do another oil change, and to do a Moly Diesel Purge.
Any suggestions on synthetic vs dino?
Should I change the filter again even though it's only been about 600 miles?

I'm wondering if doing some sort of oil flush before changing the oil, or an oil additive, may be a good idea?
Great, thanks.
O'Reilly has their diesel oil on sale so I think I'll do one change with that and then change it again to something better after another 500-1000 miles.

What do you mean by, "take it slowly"?
You mean take it easy driving with the engine, or??
thanks, that's incredibly not helpful.

didn't know if you meant something about the diesel purge process, haven't done it before
Thanks. I'm just wanting to head up to southern Oregon in a week and a half and am trying to decide if I should drive her up there.
I just went up to Mt. Shasta and back (from the bay), which went fine on the way up but she was gettin tired on the way back. I think I'm gonna see how it goes after the oil change and diesel purge and if the blowby is any better. The Siskiyou Pass can be tough on the old ones.
Supposedly the valves were adjusted shortly before I bought it, not that it doesn't need another valve adjustment...
I did a diesel purge and the smoke went down a little bit, but the blow-by isn't any better.
I actually put up another post trying to fix my blow-by:

I soaked the piston rings in MMO for three days and now have driven about 1000 miles with royal purple synthetic in there, blow-by isn't much better still.

I definitely want to do something to remove all the carbon build-up but don't want to damage things further.
Someone was suggesting using gasoline in the crankcase, as in the thread above.
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