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Inside of airbox and piping covered in engine oil (stock 2002 FD3S)
Hey guys, this will be my first forum post here, except for the introduction post.
The FD is currently sitting in the garage because of 2 things: the secondary turbo isn't coming online, and I wanted to replace the air filter.
I spent the other night removing all hoses to the airbox, and after removing the top cover, I noticed the OEM filter was covered in engine oil, and the inside of the plastic airbox also had a film of engine oil on it. Pictures below:
My first idea was that there could be a problem with the PCV system when the engine is under boost, so I checked the manual, and the PCV system seems surprisingly simple, without an oil seperator. I have an FD from 2002, and I read that the newer FD's don't have the one-way PCV valve, they just have a breather hose going to the primary turbo inlet. I think I just confirmed this, because I see 2 hose connections on the oil filler neck: one has a hose going down, the other is blocked off.
After taking off the hose from the cold side of the intercooler, I could see there is just oil everywhere.
I am starting to realize this could be a problem, and I don't really know the cause yet. You would assume that the simple breather hose is enough to depressurize the oil pan, but maybe I need to get an oil catch tank. I really hope this isn't my turbo's leaking on the compressor side. I cannot see ANY visible oil leaks on the outside, it's all on the inside of the plumbing.
Any past experiences or tips are very welcome. I have owned this car for about 2-3 weeks now, and at this moment I am stripping as much from the engine as I can, to do a major overhaul, and I don't want this oil problem persisting.
First off, since the car is new to you it's hard to say what the previous owner did to the car. That oil could have come from most anywhere.
That said, some oil in the intercooler is normal. There is a nipple on the oil fill neck that routes to the primary turbo inlet, oil vapor goes through that hose to the turbo inlet then works its way through the intercooler and pipes. Best way to solve that is to go with a catch can. You can either have one in-line that will catch the oil or one with a filter on it that the oil fill neck plumbs into and the nipple on the primary turbo intake is capped off.
You may want to post a picture of the nipple or nipples on your oil fill neck, I'm not sure how the 2002 cars were done. Mazda changed some of that system over time.
First off, since the car is new to you it's hard to say what the previous owner did to the car. That oil could have come from most anywhere.
That said, some oil in the intercooler is normal. There is a nipple on the oil fill neck that routes to the primary turbo inlet, oil vapor goes through that hose to the turbo inlet then works its way through the intercooler and pipes. Best way to solve that is to go with a catch can. You can either have one in-line that will catch the oil or one with a filter on it that the oil fill neck plumbs into and the nipple on the primary turbo intake is capped off.
You may want to post a picture of the nipple or nipples on your oil fill neck, I'm not sure how the 2002 cars were done. Mazda changed some of that system over time.
Dale
Here's a pic of the filler neck. I really think I will just install an oil catch can, and wire it the same as the OEM setup, where it also goes to the intake of the primary turbo. I just have to find a place to mount it, since the stock engine bay is so cramped! Also I will be cleaning all the hoses and the intercooler of oil
It is cheap, works perfectly, adds bling and fits nicely tucked up away by the brake master cylinder:
Looks very clean! Thanks for sharing, I think oil catch can is the way to go. I'm going to clean all intake piping and after a week of driving, I'll check the airbox again. If the catch can fixed the issue, then I shouldn't find it covered in oil.
If you think it's the PCV system or wanting to rule that out, take off the intake elbow for the primary turbo where the valve exits. If you see large amounts of oil there and on the compressor blades, then that could be the cause of the issue. If it's dumping there it'd flow all the way thru the intercooler eventually with repeated exposure. That being said as Peter noted, someone would have likely had to track the car hard for that to occur.
I'm definitely going to check that out. I got my car from japan and have no idea what was done to the car, but my best bet is the PCV system and the fact that there is no oil separation going on. Turbo's could be leaking, but I hope that's not the case. My idea is to tackle multiple mechanical problems right now (checking everything around the ratsnest, vacuum hoses and checkvalves) and then installing a catch can. If I still have oil in my airbox after that, I could have a bigger problem
I do not believe JDM cars had PCV, but i believe they still plumbed the oil filler neck to the primary turbo. The turbos could be leaking, but it could also be blow-by. Think blow-by is problem with all forced induction and tracking just makes it worse. Go ahead and install a catch can and see if you catch anything. If you don't, it's definalltely another problem.
And FWIW, i installed a baffled oil filler neck which drastically cut down my blow-by
As I noted also, if your OMP nozzles fail, they'll puke oil under load—can be quite a bit actually. Those are plumbed such that a lot of that will end up in the airbox, by way of the charge relief valves.
As I noted also, if your OMP nozzles fail, they'll puke oil under load—can be quite a bit actually. Those are plumbed such that a lot of that will end up in the airbox, by way of the charge relief valves.
P
That seems like a bitch to diagnose, or am I wrong? I went through the FSM a lot, but I haven't really seen any useful info on the OMP, and I assume this is closely mounted to the block, which means I won't see it unless I take a lot of **** off. How is it plumbed to have it puke oil that comes in the airbox? I guess if the whole intake system is coated in oil, then naturally the blowoff valve should bring this oil into the airbox. I wish there was some more info on the OMP system because I haven't really seen a lot of resources/diagrams yet...
That seems like a bitch to diagnose, or am I wrong? I went through the FSM a lot, but I haven't really seen any useful info on the OMP, and I assume this is closely mounted to the block, which means I won't see it unless I take a lot of **** off. How is it plumbed to have it puke oil that comes in the airbox? I guess if the whole intake system is coated in oil, then naturally the blowoff valve should bring this oil into the airbox. I wish there was some more info on the OMP system because I haven't really seen a lot of resources/diagrams yet...
The omp isn't too bad to get to. You can get at it from under the car, it's on the RH side next to the crank pulley. Oil lines run from the omp to the omp nozzles on top of the engine. The omp nozzles are operated by vacuum lines that pull fresh air from the air box. If the nozzles are blocked, I could see the omp pushing oil into the air box instead of through the nozzle. Although I have to believe leaky turbos would be way more common...
The omp isn't too bad to get to. You can get at it from under the car, it's on the RH side next to the crank pulley. Oil lines run from the omp to the omp nozzles on top of the engine. The omp nozzles are operated by vacuum lines that pull fresh air from the air box. If the nozzles are blocked, I could see the omp pushing oil into the air box instead of through the nozzle. Although I have to believe leaky turbos would be way more common...
I'll definitely check that out this weekend. I will also pull the vac line going to the primary turbo intake to see if that OMP vacuum hose has oil in it. I also read something interesting on the forums today:
A significant component in the health of the oil injection system is the oil delivery lines, check valves, orifices, and air source. One area I have seen that would be of concern is loose bayonet fluid fittings. The total volume of oil flow is very small and a leak at a fitting would starve the critical oil to the engine; if there is an oil film or visible oil at the bayonet fittings get it fixed; maybe simply tightening the fitting. The second and probably highest failure rate component are the little check valves that thread in above the orifices in the rotor housings. If these check valves fail and they do quite often the oil will be blown into the primary turbocharger compressor inlet (if you have the stock configuration) rather than injected into the engine. I believe this may contribute to more engine failures than many other things. I would consider the check valves a standard replacement item whenever the engine is apart. Lastly, the air supply to the check valves must be filtered clean air. The check valves are sensitive to dirt and contamination and will not close properly if there is dirt on the seat. Also, the metering orifice that is pressed into the rotor housings is very small and with oil on it dirt can easily accumulate and plug the orifice again closing off or restricting the oil flow into the combustion chamber.
So I have 3 possible causes right now: Oil is caused by PCV blowby (ideal situation, fixed with catch can), Problem with OMP nozzle/checkvalve (annoying but manageable) or the turbos are leaking oil (highly undesirable)
If you can use a diagram to locate the OMP lines, pull the air lines at the air inlet (don't try to get in to where they are on the motor, it's a bitch), cap the nipples where they went to, and plumb them to another filtered air source—like a little filter or filtered catch can. Drive and see what you get.
Maybe add some premix too, till you can rule them out.
If you can use a diagram to locate the OMP lines, pull the air lines at the air inlet (don't try to get in to where they are on the motor, it's a bitch), cap the nipples where they went to, and plumb them to another filtered air source—like a little filter or filtered catch can. Drive and see what you get.
Maybe add some premix too, till you can rule them out.
P
I'll do that I've been running premix ever since I picked up the car, if I really have an OMP issue, then it might have saved my engine, because I've been doing a lot of hard pulls till redline...
That's a great suggestion by ptrhahn. The royal blue vacuum line below is plumbed between the primary turbo and the OMP nozzles. You could easily plumb a catch can between the turbo and the vacuum manifold (shown a little up and left to the Vacuum Chamber). If you get any oil in the catch can, you know it's coming from the OMP nozzles. The other (uncolored) line attached to the primary turbo goes to the oil filler neck BTW
Not saying that it’s a definite but leaning on my stock twin car in hard corners did this exact same thing before I ran a “catch can.” Just leaning on it accelerating hard would blow some oil out.
Time for a small update. We're currently experiencing a heat stroke, so I haven't worked as much on the car as I wanted. However, today I took off the hose going from the primary turbo intake to the oil injectors, and I connected it to a T piece with a boost gauge, and a piece of silicone hose which I put in my mouth. I was able to blow in the hose without any difficulty, which is the expected behavior since the oil injectors can get fresh air from this hose. I then sucked on the hose as hard as I could, and there was zero air flow. This convinces me that the check valves inside of the oil injectors are working as expected.
Currently I have a lot of stuff disassembled, such as the UIM, all the intake piping, the air box and the air pump. I immediately saw that the check valve going to the pressure tank was literally split in half. I replaced the whole section with quality vacuum hose and a viton check valve provided by Dale Clark This is at least one of the reasons why my secondary turbocharger wasn't coming online.
I am currently in the process of ordering some more vacuum hose, because I need to hook up the oil catch can. I measured the diameter of the hose nipple on the oil filler neck, and it was 8.5mm, so I think I will need to run a 8mm inside diameter vacuum hose to the catch can. Only problem I see right now is that the catch can has 10mm nipples, so I might need to either find some smaller ones, or find a reducer to make this fit nicely.
Once I made some more progress, I will post another update, I appreciate all the tips
I had the same exact issue a couple years ago. I can assure you that it is not blow by (so no need for a catch can), and it's not the oil injectors. It's the turbos. Likely your secondary. My secondary went and did the same damn thing. Struggled to boost and leaked oil throughout the entire intake system.
Get under the car, look at the second turbo near the down pipe and look for wetness. I bet you find something. I had to take my twins off and put a good condition used set on. Boost problems fixed immediatley and no more leaks.
I had the same exact issue a couple years ago. I can assure you that it is not blow by (so no need for a catch can), and it's not the oil injectors. It's the turbos. Likely your secondary. My secondary went and did the same damn thing. Struggled to boost and leaked oil throughout the entire intake system.
Get under the car, look at the second turbo near the Dow pipe and look for wetness.
From what year was your car? I actually got under the car yesterday to check the turbo control actuator, and everything looked dry there. The only thing leaking was my oil pan on the side where it mounts to the tranny
Remember, even your 2002 is 16 years old and mileage isn't the only factor.
I'm positive it's not blowby unless you have seriously low compression. You only get blowby on a track taking right hand turns under boost as oil will shoot up the filler neck. Otherwise you won't ever have the problem with a healthy car.
The amount of oil you have is a classic case of one of the turbos going.
If you want, clean the entire intake system and intercooler and then go drive hard for a few hundred miles. See if oil gets into the intake system again. That is what I did to confirm.
Remember, even your 2002 is 16 years old and mileage isn't the only factor.
I'm positive it's not blowby unless you have seriously low compression. You only get blowby on a track taking right hand turns under boost as oil will shoot up the filler neck. Otherwise you won't ever have the problem with a healthy car.
The amount of oil you have is a classic case of one of the turbos going.
If you want, clean the entire intake system and intercooler and then go drive hard for a few hundred miles. See if oil gets into the intake system again. That is what I did to confirm.
I don't really know what the previous owner did, so I'm just going to install the catch can, replace the air filter, clean everything, and after a couple of hundred miles I'll check the intake system again, if I have oil then, then I can confirm it's the turbos.
Mine did the same thing, collected alot of oil in the IC. The only reason my box didnt have oil is because my BOV striaght off the y pip was pointed at the bottom of the car. My underside was completely soaked in oil. It was a set of new 99spec twins with 30k miles on them. Secondary oil seal was blown.
I've been running premix ever since I picked up the car, if I really have an OMP issue, then it might have saved my engine, because I've been doing a lot of hard pulls till redline...
