valve seals

[pito11213]

Hey guys

I did a search on valve seals and didnt really find too much on it for the Q.

I have had a couple of car guys suggest that I try to do the valve seals on the Q.

I am willing to try it but I would like the opinions of the members here.

Now I hope I get alot of good opinions.

Thanks.

[Altiman94]

Have you already done timing chain guides?

[elwesso]

Welcome to NICO!

The valve cover gaskets are much harder to do on a 90-93. In 94 they redesigned them for use with a rubber gasket..... For your year you will need to use RTV (IE liquid gasket).

ITs not too hard to do, just a lot of removing stuff to get it done... Ive done the drivers side and it wasnt bad at all.. Took me about 4-6 hours and that was a lot of taking pictures and cleaning the cover to PERFECTION (id eat off of it)... I hear that passenger side is easier....

What Kind of stuff have you done before...?? Its not that complicated but its certainly something you can mess up (but that goes with anything)

Also, its a GREAT time to do the spark plugs, as 90% of the labor involved with this overlaps for the plugs.. ONce the covers are off its about an extra 5mins to r/r the plugs... If you need plugs, email me ([email protected]) and Ill get you the best deal on spark plugs, on the internet......

[911/Q45]

I don't think valve seals are a problem on the Q, why do your friends think they need to be done?

[maxnix]

I agree with 911. If valve seals are shot, engine has been mightily abused with poor oil change intervals.

[C-Kwik]

If you are talking about the valve stem seals, it is quite labor intensive. Not difficult work, but it will take some time to do. It took me about a day to do and I only have 4 cylinders(16 seals). This can be done without removing the head, but you'll need a special valve spring compressor. You'll also need an air compressor with an attachment that allows you to pressurize the cylinder through the spark plug opening. A compression gauge or a leak down tester will usually have an attachment that can fit on the end of a quick connect hose.

I'd recommend having a service manual to do this. It will involve removing the cams, and the valvetrain. If done wrong, there is a risk that you might drop a valve into the cylinder. And you will be bent over under the hood for long periods of time.

You didn't note what you are trying to accomplish by doing this work. If you are going to replace the valve stem seals, I'd make sure something is actually wrong with them first(burning oil is sign that this might be a problem).

[DAEDALUS]

This can be done without removing the head, but you'll need a special valve spring compressor. You'll also need an air compressor with an attachment that allows you to pressurize the cylinder through the spark plug opening. A compression gauge or a leak down tester will usually have an attachment that can fit on the end of a quick connect hose.

Yep, I have not been able to find a "head-on" spring compressor that works. Very little room around the valves for a tool! There is one shown in the FSM though, so worst case you might be able to order one from one of our sponsors. Air pressure is one option. The other is to raise each cylinder one at a time and feed a thick nylon cord down each plug hole to keep the valves up. Good idea even with the compressed air, just in case.Others have asked and I will too: why are your seals suspect?

[pito11213]

Well I have posted before about the blue smoke i get out of the exhaust.

I have noticed that it is not all blue smoke but it is there when I hit the gas most times.

I am just looking at alternatives.

As far as oil changes all I can say is that for the last 2 years it has had constant changes, every 2500 miles with 20-50 castrol gtx. The car runs beautifully. I just want to know if it is possible that I do not have to end up replacing the motor.

I notice the smoke more when I do short trips. When I am on the highway and then come to a stop I wont see smoke, until after a while of stop and go traffic.

[maxnix]

20-50 is a little dense for year round use in NY. Is the smoke present at high vacuum (acceleration) or on deceleration?

[qship96]

20-50 is a little dense for year round use in NY. Is the smoke present at high vacuum (acceleration) or on deceleration?

Brian,you do mean{high vacuum on Deceleration} right?

[pito11213]

I just got the car from Macon Georgia. It has been a georgia car all its life.

The smoke is noticeable when i pull of from a traffic light only sometimes. When I am in stop and go traffic is smoking when i stop at the light.

I just put in some more no smoke by bardaul and it helps a little.

[DAEDALUS]

I would be hesitant to go through so much cost and labor to replace seals that are not 100% certain to be the problem. Nor is it likely to be the only problem if, indeed, the seals are faulty. Have you pulled the plugs and looked at them? Are you certain oil is not running down the plugs? Have you done a compression check?It is no small job, and would best be done along with the chain guides and--what the heck--all hoses, knock sensors, etc. Parts alone will cost well over $1k.

[pito11213]

Well my friend who i got the car from did say that when he tried to get the spark plugs changed his mechanic noted that there was oil on the spark plug.

I am aware of the valve cover seals leaking.

I just didnt think that would be the cause for this kind of smoking.

I am sure my mechanic would give me a good price on the labor

The other option is dropping 1400 plus shipping on a motorAnother 800 on labor. Alot more on parts out the ying yang.

I dont want a junk yard motor simply because you dont know the history of the motor.

Any more ideas or opinions on the valve seals?

[qship96]

based on your description,you probobly have leaking valve cover gaskets IN ADDITION to worn internals{blue smoke out the exhaust is either valve seals or piston rings,the oil is entering the combustion chamber} the oil on external plugs and plug wells has nothing to do with the oil being burned out the exhaust.sounds like the beginning to the end,price wise.

[DAEDALUS]

Unless the oil is leaking down the plugs, into the combustion chamber. It happens.

[qship96]

Unless the oil is leaking down the plugs, into the combustion chamber. It happens.

if the plugs were that loose that oil could get past them into the combustion chamber,wouldnt the car have no compression,and therefor no power,and screw up the air/fuel ratio enough to cause misfire and CEL light to go on,much less cause quite a racket under the hood?

[DAEDALUS]

I see what you're saying. I had heard that from an independent several years ago regarding a hard start condition. What is the smallest gap required to allow oil to seep? Is that smallest gap required big enough to meaningfully affect compression, given that the gap is filled with a viscous fluid? A small gap would not affect air/fuel ratio. Perhaps some debris caught under the crush washer? The plug does not have to be rattling around for such a condition to occur. I think it's possible, if not common.

[qship96]

I would think air would escape through a small opening MUCH easier than much thicker oil?

[DAEDALUS]

Sure, if there wasn't all that oil in the plug wells getting in the way.

[qship96]

Sure, if there wasn't all that oil in the plug wells getting in the way.

you believe an air gap that would allow oil to leak into the combustion chamber would win over a compression{of air and fuel}of what,up to 170PSI?

[DAEDALUS]

It's actually around 600psi during combustion. Yes, I think it is possible without knowing more. The oil has the advantage of gravity, viscosity and capillary action. A tiny gap under the crush washer is only the start, the oil would then seep down the 4 or so threads, round and round. The same path combustion gasses would have travel. The gasses might escape, but it wouldn't be much in the grand scheme of things. A leaky fitting on a sprinkler system...big deal. I don't know how much oil it takes to create visible blue smoke, but it can't be too much.

[DAEDALUS]

I didn't want to join the debate team here. I was just theorizing based on what I was told was causing a hard start on my own Q by a local shop. I redid my valve covers, replaced the plugs, and all was good. That was several years ago.

[qship96]

agree to disagree! "It does not further" lets both be glad it is not a problem we currently have,and hope some simple tests can help to solve a fellow NICO bro`s issue!

[Q45tech]

Use 2- 30 minute applications of BG Quick Clean for engines with oil changes to get the varnish off the valve stem and let the Vition seals return to round.......many times works miracles. Then after that PG Purge it [at idle] a few times..........finally use 10w30 Mobil 1 as oil if it still smokes I wouldn't waste time or money on new stem seals [$300+ in parts alone].

We have only done 2 in 6 years, both were when the heads had to be removed for other reasons.

Seen lots of ring wear from aftermarket air filters and less than good oil change intervals. We probably have dozens of smoker most over 200k customers.

[C-Kwik]

Yep, I have not been able to find a "head-on" spring compressor that works. Very little room around the valves for a tool! There is one shown in the FSM though, so worst case you might be able to order one from one of our sponsors. Air pressure is one option. The other is to raise each cylinder one at a time and feed a thick nylon cord down each plug hole to keep the valves up. Good idea even with the compressed air, just in case.Others have asked and I will too: why are your seals suspect?

I'm not familiar with the Q45 valvetrain. The KA uses a shim on bucket lifter and you basically need a compressor that can push down within the cylinder that the lifter sits. I actually bought a compressor and ended up haveing to take a bench grinder to it as it was too wide. But this kind can either hook onto a cam on a DOHC motor or it has an attachement that you bolt into the head and hook the compressor against it. It was about $50.00. If it uses a rocker type of lifter, and the spring is exposed they have screw types that hook onto some coils and pulls them up against the retainer.

[C-Kwik]

I'd probablt try a compression or leakdown test and determine the integrity of the combustion chamber. Also, try to observe carefully when the oil is burning. Valve stem seals tend to leak under high vacuum conditions(deceleration and sometimes idle).

And Q45tech is indicating the seals are made of viton. This is an extremely durable material used for valve stem seals. If these are in there, there is little chance that these have failed. My KA had some other material seals, but the replacements appear to be viton.

Here is a good link on valve stem seal materials:

http://www.automotiverebuilder.com/ar/ar79842.htm

[pito11213]

Thanks guys especially q45 tech for actually giving me something to try.

The smoke is noticeable and deceleration and at idle. You wont see when I am moving unless I have been sitting at a light for a while and then pull off.

By the way where can I get those cleaning agents that were spoken of by q45 tech

[maxnix]

By the way where can I get those cleaning agents that were spoken of by q45 tech

Try Joe at 888.216.5328 or by e-mail at [email protected] (better to call) or Ryno will have the complete line.

[Q45tech]

The BG Purge is similar to most cleaners [select by smell]: kerosene and pine tar oil, except we are just using it in this case to wash out the relocated varnish from the BG Quick clean.

The Quick Clean is highly volitle so if you leave it in too long after it desolves the varnish, the varnish will just be redeposited somewhere else.

Why you use it at idle low load low oil temp.

Any brand of oil [10w30] will do since it will only be in engine for 15-30 minutes max.

BG kit comes with MOA to add to oil during process on the theory that the Zinc will be protective if oil is diluted too much.........unlikely with 11 ounces in 6 quarts ~~5-6%.

They assume cheapo shops will not be able to charge for a preoil change and owners won't pay for 3-4 oil changes during the process.

Why we just charge $200 for de varnishing and light sludge removal......... lot of repetitive slogging in the 90 minutes. Not to mention 18-24 quarts of oil.

What would be great would be to see the car every day [spread the process out] with owner driving 50 miles [1 HR] between each daily visit.......pretty unrealistic.

[texasoil]

One thing to check asap is the PCV system. Plugged PCV will build crankcase pressure and cause oil burning for sure.