Good evening ladies and gentle men !!

I'm 99% sure my valve seals are gone after doing research. I have all the symptoms:

I'm blowing a bit of white/blue smoke when I move from a stop or when I idle for more than 5 minutes. The smoke is from burning oil. When I drive I do NOT see any smoke behind me while cruising or under boost, however if I push it to past 4.5K smoke does appear. When I do my oil change I can see the engine is burning a bit of oil. I have no temperature issues or shaft play in the T-25

Furthermore, I've done a boost leak test and found a leak in one of my injector seals. I'm assuming it was the injector seal since I could feel the air coming out from underneath. I did a compression test and the results were 178,175,150,170 across the pistons. The leaking injector seal is in the same piston with low compression

My questions are: could the bad injector seal be the reason for the low compression in the one piston...?

Is there a sure way test of knowing if my valve seals are toast?(Without actually removing them... just yet) Every test I found online just makes me look for the symptoms I already exhibit

I've read online that a leak down test would confirm exactly where I'm losing compression, has anyone ever done this test? or does anyone have the specific gauge to preform?

Has anyone ever replaced their valve seals using the "string" method? Or using the the special tool to keep them open?

The only other possibility I can think of would be worn piston rings... however wouldn't the engine would display low compression across the pistons? Also, I'd be able to feel the loss of power, which I don't

Let me know what you guys think

It's 10:30 in the morning!



No. Low compression can come from: bad headgasket, improperly-sealing valves, or improperly-sealing piston rings. A bad valve stem seal shouldn't give you low compression either.



Yes...but I forget how. I'll pass that one to the more knowledgeable guys.




I haven't actually done one, but yes this would pinpoint where you are losing compression.



A worn piston ring would display low compression in its respective cynlinder. It's possible for only one ring to be worn. You probably wouldn't be able to feel the power difference, since the compression would decrease over time.


Hope that helps.

Nope, but that's a damn good indicator that your valves are not sealing in that cylinder.

You can pull off the intake/exhaust manifold and look for oil when the valve is open.

A leak down tester would be a good thing, if you search on hear you should be able to find some homemade ones when I was asking what they look like.

For keeping them open I would just turn the crank till they are open.

There is a small chance that your rings could go, the way to test that is put some oil in the cylinder then redo the compression test.

Leak Down test!!!!! I charge $40.

Ok so I'm back to square 1, not knowing the issue LOL



By taking off the intake/exhaust I can visually see oil on the valves..? If I were to do this (which I am) would I have to replace the gaskets and would I need a torque wrench to insure proper sealing?

I read that online... So I pour some oil in the cylinder and redo the test... the idea being that the oil will temporarily plug any small holes&cracks in the piston ring... so if the compression is normal after pouring oil in the cylinder then that piston ring is donzo correct?



It's a joker quote from the dark knight

I don't think it's the head gasket since I have no other issues and I'm not burning coolant. I'll test for improperly-sealing piston rings now.

I'm slighting confused, improperly-sealing valves seems to be my issue, demonstrated by the low compression. However, you're saying a bad valve STEM seal would not give me low compression. So I'm guessing the valve has two different seals? With one at the stem..? I'll do some research now to better understand

Sorry for all the questions but this is new territory for me both in theory and practice lol

The valve seals against the head when it is closed. It's a metal-on-metal seal. That is where it can leak compression.

A valve stem seal leak can cause many of your symptoms, and it is very likely that they are the culprit. But the 150psi in that one cylinder is coming from something else.

Generally, the valves will only leak at their seat (where they seal against the head) if they're bent. I'm guessing your low compression is not actually a valve-sealing problem.

When my timing belt shredded a few weeks ago, I ended up bending 12 of the 16 valves. I still had 150psi in two cylinders. I'm not sure how that relates at all, I just thought it was cool.

I have never used a torque wrench for that stuff, just make sure it they are close to the same, and don't overtighten.

Correct if the comppression goes up significantly then that's your issue, it will more than likely go up a little even if it isn't bad.

Well the valve seals against the head.

Perfect, so I have two issues, bad valve stem seals and something causing low compression in my one cylinder... nice

Thanks for the explanation, I'll keep doing research and redo the compression test in the on cylinder

That's crazy! when my valves were bent my compression was at 90 in that cylinder.

If you have a very leaky valve stem seal you can get some carbon buildup on the valve seat which won't let it close properly. It drips down when you stop the motor and cooks on because the valve is hot.

I have a compressor adaptor that i thread into the spark plug hole and use compressed air to keep the valve in place.

If you pull off your manifolds (Exhaust first) you should see oil in the runner. Replace the seals if you see this.

Try a nice cleaning with some sea foam. Works great. The spray will get into the runners and clean the valves.

UP DATE !!!!

I just redid the compression test... oddly enough I got 170+ across the cylinders... I didn't have to add oil, and I did the one showing low compression twice just to be safe and both times it came up with 170+... Also I checked the dip stick while the car was on and there no smoke coming out which I read is also a sign of a worn piston ring... so..



Thanks Tyler, this looks very plausible. I've been meaning to do the sea foam for a while now so I'll do as soon as I can.

Should I bother removing the manifolds to check for oil? Or should I go head and replace the seals?

Just did seafoam with the help of GG Terry.. still blowing out smoke.

I'm probably just going to go head and change the valve seals and guides

I would look at the cost of that vs a good head.

I would double check your turbo before pulling apart the head.

70 bucks to change both lol the guides and seals

That's alright!

Did you look at cost of tools you will need too?

don't forget the MT-90 redline to help with that grinding trans.

yes, it'll be 35 for the tool assuming this is it...

https://www.rtmracing.com/xcart/product.php?productid=17917&cat=1502&page=2



yup 45 for 3 bottles

You won't need that to pull the head.....unless you know some magic to get the guides out. You will also need a spring compressor just do the seals.

I would just do valve stem seals. Your guides should be fine.

And if you want to borrow that HLA remover tool I can bring mine to the meat meet. The main thing you're going to need is a valve spring compressor that can work with the head on the engine.

String method is best. Just don't get the string stuck under the valve when you put the spring back on. It's not so best...

and by 'string' method you mean 'rope' right?

If you have enough string it kinda like rope. I perfer compressed air.... but you need a compressor and the adaptor

AWESOMEEE thanks Jeremy


I'll be reading up on this rope method the next few days

Get some nylon rope. Compresses niceeee. I also think I have the 4g63 tool burred somewhere in my mess. Just has a broken bolt in one of the holes due to some Dbag I lent it too

No problem.

The rope method is pretty simple. Essentially you just need something pushing the valve closed so that you can push the spring down and not have the valve go down with it.

So what some guys do is pull the spark plug out, rotate the engine so that the piston is down, then feed a length of rope down into the spark plug hole. Then they bring the piston back up, and the rope will coil up and fill the combustion chamber, pushing the valve closed. Then you're free to use the valve spring compressor and the valve will stay put.

Just don't put all the rope in the cylinder. Kinda tough to get out after

Lmao. I've actually seen this done.

This is what you want.

http://www.euroexportinc.com/store/tools/mitsubishi-4g63-valve-spring-compressor.html

Get the air adaptor and it is pretty simple to do just the valve seals. Leave the guides.

I have a feeling Sal is going to give me crap if he sees this and remembers i still haven't found time to do mine though.

It's okay, he's too busy replacing the alternator on his Mazda again, haha.

That looks like a pretty useful tool to have..

Awesome info. Thanks a bunch guys. Looks like I'll be doing first actual order from ziggy soon

I say its your turbo... valve seals usually only smoke when the car has been sitting for a while and the oil has puddles in the piston. Even at idle the oil shouldnt leak fast enough to create visable smoke. But as soon as you give the turbo any load... it will push or pull oil past its seals.

Id say get a bigger turbo while yer replacing the seals. Even if its a 14b.

Jay how would he check that? He has very little shaft play and his whole intake is lines with oil. A lot of us have looked at the car and don't think it's a turbo issue.

If he is still running a pcv he should replace that first and take his fresh air vent off the VC and and just get a filter from parts source and put that on. See if that clears it up first before diving too deep into swapping seals and turbos.

Tested PCV and replaced it already.
Pedro I would get that filter on there and try that out.

I was thinking excessive crank case pressure as well.

The amount of smoke that builds up/puffs out the tailpipe after idling for 5min tells me that its definitely not the PCV valve. that amount of smoke can only be caused by oil making its way into the cylinder via a direct leak not vapors bypassing a broken PCV.

Pcv doesnt always just suck vapours. It could very well be the seals but I would try the simple stuff first. I chased my tail 15 years ago with the same issue. Mine just happened to be a bent baffle in the VC that was allowing excess oil to overrun the pcv and pool up in the IM. Not saying that is his issue unless he recently had his VC off.

It does sound like stem seals though.

I would replace the valve seals anyway then remove the pcv and block off the intake manifold port. Leave both valve cover ports open.. after the car is warmed up .. look for smoke out the vc ports. If you get smoke.. your rings may be done. Keep in mind that worn rings or bad pcv will push oil par turbo seals.e.....

cheap... easy... if all is well then I would look for another turbo. Seals are regular maitenance anyway. and so is replacing 15 year old tiny turbos. If you still get he same smoke issue.. then Id start rebiulding a fresh motor.

Instead of the inline filter he could use one of those plastic checkvalves, I used to use the checkvalve in line with the PCV to ensure the flow was being properly controlled.

@ Pedro...I have a catch can you can have for $10, just needs a little bit of cleaning and shes good to go.

Yeah that's a good point.
Do the exhaust valve seals show the same symptoms as the intake valve seals.

Pedro, found this
http://www.dsmtuners.com/forums/art...d-block-valve-stem-seal-replacement.html

Pull the tube off the turbo's outlet. Once you see that it's not caked in oil, you can put this "oh it must be the turbo" issue to rest.

Then continue on to change your valve stem seals.

Jesus, I go back to work and you guys went off lol



As stated I've replaced the PCV valve. However, I'll get one of those filters on there this weekend and see how the car reacts.



I shall keep this in mind after I try the filter, although Alex had a nice blue shiny one I might go for instead



Thanks Bryan, that's the same article I was reading on yesterday:)



you make it sound oh so easy. I'll take a look at the turbo once more before continuing on to change the valve seals.

yes take mine!!!

Not true at all.

Gonna need to pull off the O2 housing (and ideally the turbine housing) to put that to rest. My 14b was completely clean on the cold side but burned oil on the hotside. If I took off my O2 housing (and moreso, the actual turbine housing) I could see the remains of burnt oil and it was wet around the edges of the 'seal' on the hot side.

But change the valve seals first .. they should be changed anyway. It prolly is the problem. Also open your crank case vents to the atmosphere... your only saving the enviroment with them. But if the problem still exist.. look for another turbo. Dont even waste your time with the 25.. You should be upgrading anyway.And if that dosent fix the problem... Theres plenty of spare blocks kiking around for rebiulds.

"I'm blowing a bit of white/blue smoke when I move from a stop or when I idle for more than 5 minutes. The smoke is from burning oil. When I drive I do NOT see any smoke behind me while cruising or under boost"

You haven't seen sh!t enough valve stem seals NOT to leak at idle. I doubt it's a turbo from Pedro's description.

valve stems can leak at idle... but not bad enough to make clouds of smoke behind the car. He saysvit happens at 4000rpms aswell. which means that there is alot more air going thru the system the oil leaking thru the seals. Warn turbo seals... or even bad vetalation and high crank case pressure will push oil the turbo seals at acceleration and high rpms.

Ive seen sh!t lots of leaky valve seals. My dads jimmy fills the drive way with smoke when he starts it up... Cause the oil leaked into the cylinders and puddled on the pistons. Dosent smoke after that. Not enough to notice. As soon as I put the littlest amount of load on my trubo saturn it would smoke... bad turbo.. same as my last 16g.. wouldnt smoke unless I gave it some rpms.and when It was cranking over.

It WILL make a steady blue trail of smoke coming out of the exhaust at idle. Every engine is different and just cause your dad's jimmy didn't smoke at idle doesn't mean they don't... Also I've re-read the thread and never saw him saying anything about 4,000 rpm's?

But seriously.... wh are you challanging me??? He asked us what we think. This is what I think.... its not wrong. I agree that it could be the seals. but I added that it could be the turbo. As it very well could be. I dont know where my added advise needed to be ridiculed?? My dads jimmy is an example of realy worn seals not smoking during idle or light criuse. Ive been rebiulding motors for 20 years now. Ive delt with a few oil burners. Were trying to help the OP fix his car not argue with each other about simple opinions. Thats what Tuners is for. Are you drunk and in a bad mood? You sound like 2 people I know on here already..lol.

Woah. Don't take everything to heart lmao. Don't cry about me doubting you as I could be wrong as well. Just trying to save this guy extra work. 1+ for the internet How much smoke comes out at 4k+ and till what rpm Pedro?

Sorry.. guess I was a bit grumpy after taking a day off of work to rebiuld my TB and redo my coolant system ... just for a dissapointing drag night and the evasion being cancled.

It was one time. It was a puff and I was in 1st. I did the seafoam treatment and went for a rip and saw no smoke at all and I was doing over 4k in 2nd and 3rd. Terry came with me and was looking for smoke and saw none every time. Sorry posting that misleading part and not updating

Thanks for all the help guys