what causes Valve seal to fail....


97_3clipse
07-30-2005, 06:15 PM
What causes valve seals to leak....i am under the impression that my valve seals are going bad.....
syntoms:
1) when i let the car sit over night and then start it a puff of blue smoke comes out.... only for a second...
2)i took off the oil cap while the car was idleing and a strong smell of exhaust and gas was coming from there....
3)every 1 1/2 to 2 weeks im a quart of oil low....

possiblitys ruled out:

1) PVC valve.... installed a brand new one when i installed the turbo
2) Turbo.... turbo was installed alittle under a month ago, brand new from forced preformance.

this motor is about 4-5 months old 3.5k miles on it , it was completely rebuilt from bottom up....

please post your suggestions

thanks,
Jake

joemathews
07-31-2005, 12:10 AM
Completely rebuilt doesn't mean new valve stem seals, though, correct? You can search for my threads from when my valve stem seals went. I had to drive on them for a while--it got to the point where every time I took off from a stop I'd emit a puff of blue smoke. Revving at idle, every rev produced a puff as well.

As far as I know, the main factor in causing them to blow is simply age. The little springy things on the inside edge of my seals were all deteriorated, and I had some serious buildup on my pistons from all of the burnt oil.

The Miller Valve Spring Compressor is an option if you want to replace the seals with the head on. If you do that, it will cost you maybe $50 for the valve stem seals themselves. When mine blew, Jake and I pulled the head to replace them--new HG and ARP head studs went in as well. I think my full gasket kit for the cylinder head was $120 from PartsDinosaur on eBay (including HG, VC gasket, VS seals, etc.). I would highly recommend contacting that seller for your parts--terrific service and value. If you're in a rush, or the prices are comparable, you can get the seals from the local stealership.

If you have any questions, feel free to ask. Your car will be more prone to knock with the valve stem seals leaking, so be a little careful of that with your 18g and the stock smic ;). Also make sure your oil level doesn't get too low--even 6 bolts aren't bulletproof without oil :)

joemathews
07-31-2005, 12:13 AM
Let me add that piston rings are a possibility, but unlikely. Kevin said he's virtually never heard of rings going bad on a dsm. If it is your rings, you will have awful compression (probably less than 130) in the affected cylinders. Adding a capful of oil and re-testing the compression will determine if it is indeed the rings for that cylinder.

guitarXgeek
07-31-2005, 01:59 AM
Adding a capful of oil and re-testing the compression will determine if it is indeed the rings for that cylinder.


More specifically, you need to make sure the oil you add gets to the cylinder walls and that it doesn't just sit on top of the piston dish. The compression will go up significantly if you just throw the oil in on top of the piston, but that doesn't mean the rings are bad. I guess some sort of small funnel could work to get the oil to the cylinder walls. :2cents:

97_3clipse
07-31-2005, 03:49 AM
to add another problem to the one above....
i just noticed a strange sound ,it only comes on when i boost. it sounds like a relay flickering on and off , but its to the pace of a base ball card in a spoke on a bike.....so its a pretty quick flicker....
im worried it might be the 18g...ill check it tommorow morning and reply....

97_3clipse
08-01-2005, 05:32 PM
so i check the turbo out yesterday and too my surprise it has some play!!! :banghead:

i will definatly be calling Forced Performance shortly!!
there is no reason for the turbo to get shaft play...
1)its allways had oil pressure( i know becasue the gauge never went below 20psi (~25psi at idle))
2) i dont think contaminated oil is an issuse oil, it feed right after the oil filter....
3)no boost leaks
4)i called FP and they said it was fine that i feed the turbo from the filter housing and not the head....
5)nothing was obstructing the oil feed line or return line (blew out the line and the banjo fitting with compressed air before i installed them...the oil feed line is from FP also

the only thing i can think of is a bad turbo, in olther words i got the bad apple of the bunch.

i sure hope FP see it that way.....

joemathews
08-01-2005, 07:40 PM
How much play does it have? If it isn't so much that the compressor wheel touches the housing, it's probably okay. It's normal for turbos to have some play to them. Does the turbo smoke under boost? Most blown turbo oil seals I've heard of have leaked heavier amounts of oil under boost than at idle.

97_3clipse
08-01-2005, 07:54 PM
its has 1/8th inch of play , no smoke as far as i can tell.....

joemathews
08-01-2005, 09:15 PM
1/8 of an inch is kind of a lot of shaft play; it seems like the compressor wheel should be contacting the housing if it's that bad.

If your compressor wheel isn't contacting the housing, though, I suspect your turbo is okay. Your symptoms really sound more like blown valve stem seals to me.

Are you letting the turbo cool down after driving it hard before shutting the car off? With no coolant lines, you really have to let the oil run through the turbo for at least a minute after any boosting. If you drive the car gently for the last few minutes before you shut it off, then that's another story.

EDIT> Hit up the search button DSMtuners and DSMtalk, and see what symptoms people with blown turbos had. i.e. blue smoke under boost, none at idle, or vice versa.

97_3clipse
08-01-2005, 09:21 PM
i have the turbo timer set for 30sec base time . so no matter how hard i drive its allways atleast 30 seconds... then the turbo timmer adds more time depending on the RPM signal... altho there have been a hand full of times where i just shut it off....

joemathews
08-01-2005, 09:36 PM
Well, I really doubt it is your turbo. If it is under warranty, and you don't mind pulling it off and sending it to FP, and if FP won't charge you for looking at it and evaluating whether or not it is blown, it might be worthwhile to send it in before doing the valve stem seals.

Again, search Tuners for people with blown turbos and try to see if their symptoms match yours. When I was trying to figure out if it was my turbo or valve stem seals, I decided that people with blown turbos usually blew more smoke under boost. For me, I only blew blue smoke at idle or upon taking off from a stop. As they got worse, they'd leak more. But initially, it was only taking off from a stop, or revving from a stop.

97_3clipse
08-02-2005, 05:22 PM
i Checked the turbo agian and i over exarated when i said 1/8th inch ,,it was actually more like 1/16th....

Also i called FP for support ,and they know what there talking about :bigthum:
he explianed how the center section was made and how it was designed to have play...and my center section with no water lines ususally is a little looser , making 1/16in play normal... we got into another dissucion about the blue smoke and some sounds i have been hearing.... well it turns out with no water lines im getting a higher oil temp. inturn making oil thinner. so im hearing some of the rotating assemblys noise that is usually masked by the oil..i can only hear this faint sound after acuople good hard pulls....(oil heats up)then after the car idles and cools down its goon... the only way i can hear it is if i get on the gas...if i drive like a normal human being its fine all day.....so as soon as i fix the leak on the oil pump i will be installing a aftermarket oil cooler from diamond star motor sports ...
http://www.diamondstarmotorsport.com/engineparts_files/ss-oil-cooler-kit.jpg
and yess i do have a 90 style oil filter housing.... hopefully that will solve the oil temp problem....or i may have to move to thicker oil...

the blue smoke is from the PVC valve... when i got the new one it wasnt function right and i bought another one and no blue smoke :nutkick:


so basically this thread and my stress over the last couple days have been worthless :banghead: concidering there is NOTHING wrong with my car.......


happy turbble hunting,
Jake

joemathews
08-02-2005, 06:35 PM
Great to hear that it was a minor problem!

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