what's good for leaking valve stem seal?

Status
Not open for further replies.
Joined
Apr 11, 2004
Messages
4,005
Location
los angeles
95 Camry. I think that one or more of my stem seals leaks because when i first start up the car smokes.What can i use to stop this,besides auto-rx?
 
Not much, valve stems seals become hard like plastic, and often crack and fall apart. Aside from a thicker oil, a HM oil, or replacing the seals there isn't much you can do.

AD
 
Not much will fix valve stem seals except replacement. HM oil and/or a thicker grade might be all that you can do.

frown.gif
 
Originally Posted By: StevieC
Not much will fix valve stem seals except replacement. HM oil and/or a thicker grade might be all that you can do.

frown.gif



Maxlife 10W-40 has done the best for me with this type of issue. It is readily available in most places and on sale often or about $14 for 5 qt jug at WM.
 
I see all the recommendations for a High Mileage Motor Oil. Are the additives really that good? The only pure synthetic HM oil I've seen is Mobil 1 and Valvoline Max Life. I wonder if the formula is any good since the M1is not SM certified and the 5w30 has a higher viscosity index than the 10w30or40 for both! Then I have to wonder why Mobil or Valvoline don't make a popular engine additive separately?

http://www.mobil.com/USA-English/Lubes/PDS/NAXXENPVLMOMobil_1_High_Mileage_Oil.asp
 
Last edited:
I have some Maxlife engine protector bought at Big Lots. Looks like Valvoline does not make it anymore. I guess it was not that popular.
 
I wonder what they use in Maxlife to "restore" valve stem seals. Viton is tough stuff and almost chemical proof. From my understanding you'd destroy it with any chemicals that would "soften" or "condition" it.
 
SM oil is not always an indicator of the better quality oil for a particular application. SL sometimes means that a particular oil, such as M1 HM, simply has an older, higher (better) level of anti-wear additives such as ZDDP, which was limited even more for the newer SM oils of certain viscosities.

If an engine is leaking, common sense tells me to stay away from more expensive synthetics and use one of the HM blends, at least until the leak stops. Maxlife blend works great here. It works way better than some of the common stop leak additives, in my experience. I have less experience with the other HM oil brands.

Also, not all valve stem seals are made of Viton.
 
Last edited:
Condition the valve seal, hopefully, clean it up, yes. Whatever, it works for me. MaxLife blend & full syn are at the top of my best HM oil list.
 
I always thought it was marketing, but I have found out that they do in fact use a specific chemistry for seals, and apparently it does work.
 
IF that's the problem.

A few other things can cause a bit of smoke at start up.

Does the car smoke when you take off after idling for a while?
How about at high rpm/high load?
Compression? Leak down test? Hows the PCV? Is the intake full of oil?

Sure there's no harm in playing with the oil, but it can't fix everything.
 
A HM oil might help. Typically I've seen in older cars the valves stem seals become brittle and hard as plastic. These can actually crack and break. If that is the case all bets are off with HM oils. Then the next plan of attack, (other than proper repair) would be a thicker oil, or something along the lines of STP, or Schaeffers #132. #132 is a great product especially in older engines, or engines that use oil. JMO
 
Check the drain back holes in the head,make sure they are clear and the oil isn't puddling.Also check the PCV.

Too much is made of valve seals they actually do very little as far as oil control goes in some engines (old big block Buick engines only used a skinny o ring type on the intake valves,none on the exhaust the intake only sealed when the valve was in the down position).

You may well have sticky rings,the heat of the cat as it warms could be burning it off.
 
Status
Not open for further replies.
Back
Top