Oil smoke question Options

[isdyl]

Hi, I wonder if I could get some advise please. I've bought a 1974 1.7 which was imported to the uk and I'm currently restoring. I noticed the oil level was above the maximum but thought I'd deal with that before starting the engine. I had to do some welding underneath and jacked up the passenger side quite high to gain access, and a load of oil came out from somewhere on the drivers side! I couldn't see where it came from but must have been about a pint/half litre. Anyway, I got the car running just afterwards and it sounds fine. Only problem is that after it warms up (about 5 minutes) it starts belching out white/grey smoke from the exhausts. There is also a fair amount of oil ON the exhaust which starts burning off too and the whole car stinks of burning oil! I think the oil ON the exhaust should burn off soon enough, but is there a chance that I have somehow filled the exhaust with oil by tipping the car up? Or could it be something different/worse? It has an after market sort of 4 pipe exhaust system which is rusty and looks a pig to get off. I'll try and add a photo.
Many thanks for any advise. Regards Dylan

[falcor75]

That it starts smoking after its warmed up is odd. If oil was leaking past the rings or guides it should smoke the whole time? Or if something expands from the heat and then starts leaking. You could check with a piece of steel wire that you dont have oil sitting in the exhaust

[iankarr]

My guess is that the pushrod tube seals are leaking oil onto the heat exchangers...and possibly there are rust holes on top of them, allowing oil to seep in. Then, when the heat exchangers warm up a bit, the oil in and on them begins to smoke. Just a guess, but that might explain the smoke and the timing.

[isdyl]

Thanks for the ideas - most of the burning oil smoke is definitely coming out of the exhausts - I'll try pushing something up them but not sure I'll get all the way to the first 'low point'. My guess was that oil filled up the rocker cover when it was tipped up, and some leaked out from a bad rocker cover seal onto the exhaust. The rest may have gone down an open exhaust valve - is this possible??
Thanks, Dylan

[Ansbacher]

Five minutes then smoke- those were my exact symptoms when I had bad push rod tube seals on my first 914 way back in 1984.

Ansbacher

[iankarr]

Thanks for the ideas - most of the burning oil smoke is definitely coming out of the exhausts - I'll try pushing something up them but not sure I'll get all the way to the first 'low point'. My guess was that oil filled up the rocker cover when it was tipped up, and some leaked out from a bad rocker cover seal onto the exhaust. The rest may have gone down an open exhaust valve - is this possible??
Thanks, Dylan

Does the smoke through the exhaust continue until you shut the car off? Or does it dissipate?

[isdyl]

Seems to keep going but I haven't run it longer than about 10 minutes idling/reving a bit. Concerned about push rod tube seals - is that major problems? Does it normally take a while before smoke starts to appear? I have 15/40 oil in it at the moment as I did a change and that was cheap and available. Could that be too thin and cause a problem like this please?

[Mark Henry]

Oil is fine, 15/40 is what I'd recommend for your climate.

Seals or rust through on the PR tubes dumping on the exhaust is also what I would first suspect.

[Mark Henry]

Also check your valve cover seals, old ones tend to suck in causing leaks in the cover.

[Mark Henry]

Just an FYI the PR seals/tubes can be done in car except cylinder #3.

You can, if you have extra jack stands, remove the shift rod, loosen the trans bolts and drop the nose of the engine down 3-4 inches. This will give you enough room to do cylinder #3 without a full engine/trans drop.
PITA but do-able.

[Dave_Darling]

The "jacked up the right side and oil came out the left side" makes me wonder about the thermostat pulley. The bolt that holds the pulley onto the side of the crankcase is a through-bolt; sometimes when people disconnect the thermostat they remove it and the pulley, which leaves a nice hole into the inside of the engine.

If that's what happened, double-check that you actually do have cooling flaps installed under the engine tin. There should be a cross-shaft running left to right across the top of the engine, in front of the oil filler, just aft of the fan shroud. There was a school of thought that removed these flaps, reasoning that they only got in the way of air flow. (That school is wrong; they direct air flow properly!)

Agreed that smoke from under the car after 5 minutes is a typical symptom of oil dripping onto the top of the heat exchangers.

Is the smoke out the back of the car actually out of the tailpipe itself? If not, then oil leaks onto the top of the exchangers are the main suspects.

--DD

[Rand]

As Dave asked... WHERE the smoke is coming from is crucial. If it's burning off of engine / exhaust bits, that's very different than if it's coming out the exhaust.

[motorvated]

When I first got my '75 1.8 L-Jet it would idle crazy high and after a few minutes, it would start smoking severely out the exhausts. Looked like white to gray smoke, not blue like oil. Dropped the oil and there was quite a bit of gas in with it. Seems like there was unburied gas in the exhaust that once hot enough started burning with the residual carbon that was in the exhaust system. I thought the motor was toast, but once I got the FI sorted and the exchangers and muffler cleaned and replaced, the smoke was gone and never returned. Just a possibility.

[jcd914]

If you jacked the car up at enough of an angle and let it sit that way long enough.
You could have filled the rvalve cover/rocker area with enough oil to get some into the intake and exhaust through the valve guides. The heads don't have valve stem seals that would keep oil out if the valve cover/rocker area was full of oil.
Oil inside the exhaust will take quite awhile to burn out.

Jim

[isdyl]

Many thanks for your advise on this.

The shaft isn't there but the pulley is. I've tried to attach a couple of photos if they help, but I think the oil which got ON the exhaust is a separate issue to the smoke actually coming out the tail pipe. It is a white/grey smoke which actually comes out of the pipes, very much like the white vapour you get on a cold day.

I was also interested in the over fueling possibility. The car has been converted to a single 32/36 weber and has an electric fuel pump. When I switch on the ignition the pump starts ticking, but on previous cars I've had the ticking stops when the carb chamber is full. This doesn't stop ticking at any point before ignition. Could this be the smoking problem? Maybe completely unrelated to the oil??

[isdyl]

If you jacked the car up at enough of an angle and let it sit that way long enough.
You could have filled the rvalve cover/rocker area with enough oil to get some into the intake and exhaust through the valve guides. The heads don't have valve stem seals that would keep oil out if the valve cover/rocker area was full of oil.
Oil inside the exhaust will take quite awhile to burn out.

Jim

Thanks Jim - this is what I suspect and hope has happened and that it will eventually burn away. I just wasn't sure if it was possible. Regards Dylan

[iankarr]

Hi Dylan,

I think you’re at a bit of a “come to Jesus” moment. What I’m about to suggest will involve some work, but is probably the shortest path to enjoying your car to the fullest.

A single carb setup is not advisable with the type IV engine. The intake runners are too long, and it will be very difficult to get the motor running right. Between that and this smoking issue, I think getting the problems sorted will be like playing with a rubik’s cube. If I were you, I’d....

- Drop the engine and change all pushrod tubes/seals, oil cooler seals and valve cover gaskets. Also check the oil pressure sender area to make sure it’s not leaking from there. Do a valve adjustment while you’re in there. These are all inexpensive and simple things that should be done to get the car to baseline anyway, and it’s much easier to do with the engine out.

- Remove the single carb and go back to stock fuel injection. If that’s not practical, go with a proven dual carb setup with a cable-synced throttle. You should be able to keep the Weber you have and just add a matching one. Make sure they’re configured the same.

- Check the condition of the exhaust system...especially from above. Re-reading your first post about the rusty pipes, I’d bet there are holes in the top which are letting oil dripping from the engine into the pipes. I can’t tell definitively from the pics, but the heat exchangers look to be stock. The monza-style 4 pipe muffler isn’t, but if it’s intact it should work fine.

- Clean any old oil off the HEs and engine.

I suspect this may clear up a lot of problems, and if some remain it will be a lot easier to diagnose because you’ve reduced the chances that multiple issues are conspiring. These engines are simple and reliable, but the more you deviate from stock, it seems the more finicky they become.

The awesome community here will help you every step of the way.

Just my .02!

[motorvated]

When you converted to the carb, I'm assuming that you also changed out your fuel pump for a low pressure one, or installed an inline fuel pressure regulator to drop the pressure down low enough so you don't blow fuel through the carb float valve.

[isdyl]

Hi - great advise thanks, and that is definitely what I intend to do regarding the carbs. I have actually been looking out for a pair of weber 40's, but even used and with the manifolds and linkage I'd be lucky to get them for £400 or £500. The exhaust heat exchangers are rotten and just rattling around on the exhaust. The exhaust itself is rusty, but solid.
Just to explain a bit more the situation, I bought the car really cheap as it had a lot of rust in the floor pans, but also the bonnet had flipped up smashing the windscreen and damaging the skuttle below the windscreen. I have been repairing all of this damage along side getting the engine running. It is an import from Canada and as yet I haven't been able to register it here in the uk as it needs to be road worthy. As soon as I get it road worthy and registered, I can then insure it, and I really want to drive it before I spend too much money on it. I would like to make it as stock as possible, but I've had d-jetronic on an old SL mercedes a few projects ago and the parts were massively expensive in the uk so will probably stay with carbs.
I think the fuel pump had been changed, but not sure as I've only had the car for a couple of months. I've attached a photo of the pump. Odd looking square thing. I think the original pump was a bigger cylinder shaped thing?
I will probably get a second car soon in better condition if one comes up at the right price - I'll like a stock injected 2.0 ideally. (or a 6! but thats just a dream...)
Regards, Dylan

[isdyl]

The smoke seems to have cleared if anyones interested. Must have been oil in the exhaust after all. Thanks for your suggestions.