Smoke at idle

[Frodo the Zuk]

I've exhausted my research and need opinions.

I have an 87 Suzuki Samurai sporting a 1.6 VW diesel. I installed the '84 1.6 NA myself about 12-13 years ago. Just after a ring job, I sold the vehicle. That was 11 years ago. I loved that little Zuk and missed it terribly. Fortunately for me, I was given the opportunity to buy it back, and I brought it home about 6 months ago. New owner added an '86 hydraulic turbo head and T3 turbo, boost and EGT gauge, 2" exhaust and external oil cooler. Very nice setup. Runs very well. Yes, it's an NA block with a turbo head and turbo. I watch the EGTs closely, but never touch 1400.

I've checked and adjusted timing. Right now, it's at 1.05. GPs are new. Injectors have been rebuilt and pop and spray equally at 155 or thereabouts. Runs like a top. Starts easily (maybe a little wobbly until warmed up). But it is smoking at idle and uses a ton of oil. I went through 2.5 gallons of Rotella T4 in just under 3k miles. Smoke is white/blue. Come to a traffic light, and it smokes. Embarrassing amounts sometimes. Pull away, all clear. Stop at drive through ... smoke. Gotta shut down at the window. And then sometimes it just sits and purrs. For example, I answered a call yesterday, pulled over to talk, and the little diesel idled nice and smoke free for a 5-minute conversation.

From the reading I've done, I'm either looking at valve stem seals or turbo seals. Those that say valve stem seals strongly recommend rebuilding the head. Those that say turbo seals recommend a rebuild kit, no big deal.

Given my symptoms, what should I do?

[ORCoaster]

In all the information you don't mention the cylinder compression.  Could it be that over the years and miles of running that turbo set up the rings are again in need of replacement? 

Turbo rebuild sounds like a good choice as well.  As well as the valve stem guides.  Both of those are high on the list for high oil consumption. 

I think if this was me I would check compression, then rebuild turbo and leave head rebuild for last.  But that is just me.


As a last thought how about the drainline on the turbo.  Does that flow freely to the oil pan?  Could it use with some cleaning?  Backing up oil in the turbo perhaps?

[Frodo the Zuk]

You're reading my mind regarding the order of attack. I haven't pulled compression yet because I don't have a tester that'll fit ... and considering how recent the ring job was (in mileage, not age) as well as the inconsistency of the smoky show and how well it starts and runs, leads me to think compression is OK. But I know I should check it, if only to rule it out as suspect.

The turbo drain line is a straight shot to a 90-degree elbow fitted to the top edge of the pan. I understand that the 90-degree bend is very much less than ideal, and it'd be easy enough to correct that and rule it out. I am also curious to know if there is a restrictor on the feed line like some recommend. A rebuild looks easy and isn't expensive - it may be worth just doing. That would clear up the drain, let me know the condition of the feed line, and refresh the seals.

Obviously, I'd really rather not pull the head. But if all else checks out, it is what it is.

I guess what really confuses me is the inconsistency of the issue. Sometimes the smoke is heavy, sometimes light, occasionally clear at idle, and not an issue at all while cruising.

[ORCoaster]

The inconsistent smoke might be due to oil at higher pressure when cold but that wouldn't explain the smoke when getting a coffee or doing the bank stuff at a window.  That sounds like seals to me.  It was running hard and then not.  So oil going in is now more noticeable due to less RPM.   And no forward movement. 

Correct the 90 degree elbow with a 45 and that way the drain wouldn't be suspect any more.  Free draining and not potentially settling out a chunk or two of something at the edge of the oil pan producing a backup

[zuhandenheit]

My understanding is that turbo oil feed line restrictions are unnecessary / a very bad idea on these motors.

Have you looked at your intake pipes? Does your crank case vent go to the intake? If not, there shouldn't be any oil in your intake pipes. When I had an inadequate oil drain, my post-turbo intake pipes were all coated in oil, and oil was even seeping out of the turbo housing and dripping off the wastegate actuator.

[burn_your_money]

Do the valve stem seals with the head installed. If it fixes the issue great, if it comes back in a few months you know what to do (rebuild head).

[Frodo the Zuk]

Just want to report that I have not had time to dig into the issue. I hope to do so next week. I do think my timing is retarded. I've set it by the book to 1.05, but it seems to beg a bit more advance (idles good with cold start cable out, not so good with it in). I'll set the timing "hillbilly style" asap.

Needing extra advance leads me to think about rings... but rings wouldn't smoke like this, would it? The smoke is inconsistent, and rings wouldn't be inconsistent.

The smoke this morning was ZERO at startup, zero at one red light, and zero through the unusually long wait at McDonalds 6 miles later. But it returned, abeit not as heavy as before, at the schoolhouse (I am a teacher).

[burn_your_money]

It could be intermittent air in the fuel causing the timing to retard.

[Frodo the Zuk]

I have clear lines to and from the IP ... and no visible bubbles.

[Frodo the Zuk]

OK, get this:

No smoke on the way home from work yesterday. No smoke this morning. Smokelessly idled through Burger King and every traffic light. And it's running perfect (with the cold start out - haven't advanced the pump yet)...

So ... has it repaired itself?

Maybe there was air in the IP from a recent injector nozzle replacement that finally worked itself out. Perhaps the couple ounces of SeaFoam I added to my crankcase two days ago cleared up a stuck ring or blocked IP drain. Who knows?

The 2oz of SeaFoam in the oil (Rotella T4) seems to be the logical catalyst, though. Interesting.