tannerezell077

Hello i am trying to solve a problem that just happened with my ka24de turbo build. After bleeding the cooling system the other day and putting in a new thermostat once my car started to get hot(fans unplugged) it started firing off three cylinders. I figured out that cylinder 4 had pooled up with oil and fouled the plug. Replaced the valve cover gasket and checked compression they both turned out okay. No coolant and oil mixing or anything like that but i do smell gas in my oil. The oil seems pretty thin and definitely has gas in it probably because my injector/fuel rail spacer needed to be replaced. I fixed that and started having this issue a few days later. It smokes bad after about 10 seconds after startup. Could my oil be really thinned and it causing it to leak through my old valve seals on #4? I feel like the gas in the oil is the root of the problem but for all i know it could be my rings. any help?

unicoder

Gas will thin your oil out so much that it becomes as like water. This will wash out your cylinder and blow the engine.

1st - Have you resolved your injector issues? Are you sure one isn't stuck open and they are all firing correctly?

2nd - If your injectors are working correctly, change the oil immediately and see if the gas returns to the oil, if it does your rings may be gone

Also, you said compression was "ok" what numbers did you get? Were they consistent across the board?

I also have a turbo ka24de and started at 160psi on all 4 cylinders but you know how boost does on stock engines, after a few months at 10psi of boost I now have 120psi on all cylinders and gas in my oil. This is typical of boosting on a stock engine that is about to need a rebuild

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tannerezell077

i did resolve my injector issues i put new rubber o rings and spacers and the injectors themselves are brand new. i also pulled the fuel rail and cranked to make sure they’re all working properly and they look perfect

i have had smoke on startup and idle before i even went ka-t due to bad valve seals which i need to replace anyway but i’m thinking the valve seals on cylinder 4 tore completely out of shape which would be why the oil seems to be seeping and filling the cylinder.

compression was all right close to 150 on all but they seemed to rise a little when adding oil. i am not convinced it’s my rings seeings how it just suddenly started smoking and misfiring bc of the cylinder filling with oil all at once i figured rings would slowly start to go bad


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Kingtal0n

This sounds like you ran a MAF sensor and no recirculated bypass, washing the oil off the cylinder walls repeatedly. Either that or the coolant temperature was kept too low.

It isn't boost pressure. SR20 have stock cast pistons and go 150k with reasonable compression. With a bypass recirculated MAF setup. If you drive below sea level the air becomes more dense just like if you drive up the side of a mountain. That doesn't directly, immediately affect cylinder wall finish/longevity. Force to the surface of a piston is pressure over area whether "boost" was involved or not.

Kingtal0n

Gas in the oil because the tuning is probably no good. A/F wideband should say 14's and 15's all the time except WOT thats when it says low numbers 11's 12's ish depends on how hot the setup is.

The 14's and 15's keep the plugs clean and carbon fragmenting to a minimum. This plus the residual oils from cylinder wall scrape leavings and valve guide seepings make the total carbon fragmentation soup.


If you are seeing excess soup then it is in excess bypassing one of these oil seals, again they are valves, rings. Between the 14's and minimal valve/ring seepage the combustion chamber can stay somewhat clean. Still the piston tops, valve and other areas develop hard black carbon solid crystal structure coating. To remove this we can pull the head and decarbon manually (I used mineral spirits recently and a brush) or for a running engine we can inject 100% Distilled water using a typical water/meth kit. This is only done once the combustion chamber health is verified (no appearance of oil, so you are not ready yet). Oil could also be coming in through some pcv ducting but we are assuming/hoping/warning you have to have taken care of and examined the pcv ducting, both fresh air inlet side and low pressure manifold suction sides, and become familiar with these routes, since it is by far the most important system next to the oil system on a performance engine.

So to re-cap. Its running too rich 11's 12's 13's all the time and thats why fuel in the oil and oil smells like fuel now. Needs significant tuning
2. Oil getting in through valve, ring, or pcv. Many methods to diagnose these. First step is find out how much is leaking. If it was my engine I would clean the chamber with brake cleaner, spin the motor by hand with the plug out and clear the oil if there isn't too much. Then see how fast it runs in. If its too much oil you have to take it apart and measure everything. This is why I never let anybody touch anything on an engine that needs to be reliable, unless there is a significant track record. Like if you saw a company on ebay that has 500,000 feedbacks for selling heads and 100% policy etc... if the price was very low and they claim to be OEM quality all of this adds up to a reasonable expectation to get a good product. If on the other hand you go through yellow pages and find a random machine shop that claims they can machine your head, you get there and its full of V8 stuff all over the place, and filthy machines. This is all too common unfortunately and your head could be the first one they ever did for that engine. That is not a good track record. When it comes to these engines (particular 4-cylinder applications of all kinds) you need to find "the best guy in the business" type of shop for that particular engines. You know, places that spend obvious hundred thousands of dollars developing the platform. Like for sr20 in Florida you can't ignore Mazworx. You just can't. And I just don't think any of those ever existed or will for the KA24DE, not the way you and I meant it. Like, there is no Mazworx for the KA24 platform locally accessible at least for most of us. The way it is for sr20. For example some places have computer scripts for machining specific SR20 port designs that have already been put to use/tested. You can just duplicate the same great flowing head and machine work reliably with enough investment. THATS the place you need to buy heads from, but where is it? Where...

tannerezell077

how do i check my pcv? i don’t have my catch cam setup yet and i’m thinking s lot of blow by might be a piece of my issue.


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Kingtal0n

examine pcv systems in general. The crankcase is like a cup, imagine there is a cup in front of you. The lid keeps oil in the cup (valvecovers can be lids). To let pressure out of the the cup there is a hole in the lid somewhere. To let air back into the cup there is another hole in the lid. So 2 holes. One only flows one direction (PCV checkvalve side), the other is open to the air all the time (air filter side). The air filter side needs free unobstructed tube or the pcv checkvalve side will feel a vacuum signal and start pulling oil into the tube where it connects to the intake manifold.

So thats your shortcut clue. The intake manifold has a hose that runs to the crankcase lid with a check valve inside it (pcv valve) and that is the most likely place to suck oil during normal operation. I would say look inside the intake manifold for a stream of oil running from the check valve tube into the head/valve area.

The other possibility is during boost you pressurize the crankcase. Thats when the fresh air tube spews oil all over the place on the other side. This tube is usually attached to the compressor inlet.

So, 2 tubes,
1. compressor inlet to valve cover
2. intake manifold -> pcv valve -> valve cover

#1 blows out during boost if there is a problem
#2 sucks oil during cruise if there is a problem