Stephan@MX5

Hi guys,

This is the quantity of oil what is coming out of the drian of my Greddy turbo
My turbo is recently been overhauled, but is this the correct quantity?
Seems to me too little?

The reason why is asked this, i have massive smoke problems with the cold start, after a few seconds the smoke stops.

This is the first start since a month when i recorded this video, so you can ignore the noisy HLA's

AlexL

The only time is smokes is after a cold start? Turbo seals usually smoke the more you beat on the car, not just after sitting.

Traditional thinking would say that you have oil leaking past your valve seals and dripping into the combustion chamber but I see your thread which says this engine was just rebuilt so that seems unlikely too.

As long as your turbo oil feed line is correct then I don't see why your turbo seals would have any issues. I've never seen an oil drain tested using the method in your video before.

curly

iTrader: (25)

That looks perfect. If your oil pressure gauge is showing a decent 50+psi on a cold start, you'll be getting that into the turbo, and it appears to be draining just fine. If there was enough oil going through the exhaust for you to notice a lack of drainage, you'd have a GIGANTIC smoke cloud behind your car.

Smoke on cold starts sounds like it could be valve seals. Whens the last time the head was rebuilt?

Stephan@MX5

Oke guys, here is more info!

Yes, only at cold start. After a drive of about 1-2 minutes its gone (at least the heavy smoke what i can see in the mirror).

It is correct that my engine is rebuilt, at this moment it has not run for more than 1000 miles.

I use the stock Greddy feed line, and tested the quantity of oil what is coming out when i crank the engine, that is much more than the movie above. Ok, at that time the feed line has no resistance.

The downpipe and piping to intercooler are clean of oil.

Here is a (bad) picture of the oil pressure (cold start).


And this is the result of a few seconds on idle

curly

iTrader: (25)

Right, the feed line is pressurized, the drain line is not. Which is why it needs to point down all the time, since it's gravity fed. The feed line will look like a lot more oil than the drain line.

Any restrictor in the feed line? I don't think the greddy needs one, but it's something to look at.

hornetball

iTrader: (4)

Just theorizing, but if the turbo oil seals were a little weak and the oil pressure spikes on cold start, perhaps you are overcoming the seals until the oil warms and the pressure falls. Kind of how a cold start overcomes the pressure by-pass in an oil filter.

Think back -- was this your sequence?
1. Car fine.
2. Turbo removed for rebuild (nothing else done to car)(why would you do this if #1 was true?).
3. Turbo re-installed and car now smokes.

If so, then the turbo is the likely suspect. If not, what else was done to the car immediately prior to the smoking issue?

Joe Perez

iTrader: (8)

The stock kit didn't have one, nor did I use one with mine when I replaced all of the lines with AN hardware.

I wonder, along the lines of hornetball's question: could oil be leaking past the seal on the turbine side?

I'm trying to come up with a way for this smoking to occur for a full 1-2 miles after startup if it's valve seals. Seems like that would clear after just a few seconds.

AlexL

Well he says "1-2 minutes". A couple drops of oil leaked past seals has the potential to produce quite a big cloud.

I like Hornetball's troubleshooting method though, what changed? What change prompted the smoking...?

Stephan@MX5

Okey, i tell you guys the whole story,

Engine was not fine, belt of the waterpump broke on a sunny day wich i did not notice (sun into dash, did not see 'charge' light). Result: crooked head.
Before that i had already smoke problems as described. People around me told me, "oh, that is your turbo!" That is why i let it repair.

So my head was crooked and let it completely overhauled, it was now dismantled anyway, and wanted to get it right (valve seals are new, not OEM).

A closer look to the cylinderblock i came to the conclusion one piston was in a bad shape, so i installed new pistons, bearings, and so on.

So i thought, what can go wrong now? Overhauled turbo and engine, it is ready for thousands of miles!
Conclusion: everything is new, bud did not help me at all

One more thing, at start up it takes about 5-6 seconds before the smoke starts.

hornetball

iTrader: (4)

That's a lot different.

How sure are you that it is oil smoke and not steam?

Issues getting head gaskets to seal are not uncommon.

A metal crack that changes its behavior as the temperature changes (either goes from closed to open or vice-versa) is also not uncommon. Was the head and block magnafluxed after your overheating event?

Joe Perez

iTrader: (8)

If there's one thing we love here at MT, it's a hole story.



So, yeah.

Smoke or steam? Good question. Is it stinky and bluish-grey, or slightly sweet-smelling and white?

18psi

iTrader: (76)

Stephan@MX5

Sorry, missed the w, sounds funny this way

It is for 90% sure oil, it smells like oil and i had to top up the oil a few weeks ago, not much. Smoke is bluish-grey. Coolant stays at level.

The WHOLE () engine is securely assembled, not one crack is noticed.
What could I have done wrong about the OEM head gasket?

Hornetball, what do you mean with magnafluxed? Detecting cracks?
For head and block, don't know, have to asked the repairer.

curly

iTrader: (25)

Well, wouldn't a compression and a leak down test eliminate all but the turbo?

Stephan@MX5

Don't know! Also if a valve seal is incorrectly mounted (for example)?

Compression is in all 4 the cylinders around 180 psi, what i can remember of the last test.

hornetball

iTrader: (4)

Sorry, yes "magnaflux" is American-slang for a dye-penetrant crack inspection that uses a black-light to detect cracks. Pretty effective. Helps visualize metal cracks that may be impossible to see with the naked eye.

I agree with the suggestion to do a leak down test. It can't hurt.

Really, what we're after is looking at likely causes before we go down a path that most other members haven't seen before. We're saying that we don't suspect the turbo because with the experience base here, if this happened a lot someone else would have seen it. For example, several members have experienced new head gaskets that didn't seal properly -- usually because the mating surfaces on the head and block weren't sufficiently prepared.

Beyond compression or leakdown testing, some other tests:
1. Start car and as soon as it begins to smoke, turn it off. Inspect turbine wheel for oil. Inspect inside of exhaust manifold for oil. If there is oil in both places, it's coming from the engine. If there is only oil on the turbine wheel, we're looking at turbine seals.
2. If you still have the stock exhaust system, perhaps you can put your OEM header back on and remove the turbo for a drive. Do you still have the smoke?

Stephan@MX5

Thanks for your reply.

I will ask the repairer/reviser if it's magnafluxed, good explanation!

I have now reached the point of disassemble the turbo an manifold and mount the OEM header and exhaust, received an second hand OEM muffler last week.
It is radically, but makes a lot clear.

I'll keep you updated.

Stephan@MX5

Oh, what about the oil? I use Castrol 10w40 semi synthetic, advice of the repairer/reviser.

Stephan@MX5

Okay,

Last week i have build everything to stock, result: engine is still smoking after start up.

Thanks guys for your input, let´s have a conversation with the guy who rebuild my engine

Stephan@MX5

Finally had time to disassemble the head to bring it back to the guy who rebuild my engine, for me it was immediately clear: valve seals! Why? Oil on every piston

He phoned me today, he came to the same conclusion, valve seals, dúh!
The cause is an other type he mounted, but how that is possible I don't know.

Other fact is, I can throw my head gasket into trashcan, but he's compensation is MLS gasket for free

Thanks guys.