Main seal leak on 1997 850 GLT

[Eric Raas]

I just switched mechanics and the new service advised me that the main
seal on my '97 850 GLT (107k miles) is leaking. He attributed this to
a partially blocked breather tube, and suggested a short-term
workaround of leaving the dipstick slightly withdrawn to allow
additional air exchange into the motor.

The longer term fix is of course main seal replacement, at about
$1,400USD. Nothing sounds particularly unreasonable to me, but would
be interested in any comments on this scenario and options. I am
looking to run the car for another 1-2 years/50-75k miles at least.
Up to $3k repair/year it's still preferable to a new car for me.
However I may exceed this as the Boston roads are leading to at least
one major suspension job per year as well. Ten months after replacing
virtually all the suspension front and rear my new mechanic advises
that control rods are near shot again. I believe him as with the
wheel cranked (e.g. U-turn) I can feel some unnatural play and get
some knocking sounds. I have to say the overall feel of the car on
our rough roads does not inspire a lot of confidence...

On a related note I had a front brake caliper replaced that would
stick after about 1/2hr of driving. Mechanic advised that these
should be replaced in pairs to match hydraulic characteristics, so I
did the other front caliper as well. Does this sound reasonable to
anyone knowledgeable out there?

Like I said the mechanic seemed pretty reasonable (for all I know he's
reading this). I'm just trying to gauge whether I'm sinking too much
money into an aging car.

Thanks in advance for any comments,

ER

 

[Dan Behr]

I just switched mechanics and the new service advised me that the main
seal on my '97 850 GLT (107k miles) is leaking. He attributed this to
a partially blocked breather tube, and suggested a short-term
workaround of leaving the dipstick slightly withdrawn to allow
additional air exchange into the motor.

The longer term fix is of course main seal replacement, at about
$1,400USD. Nothing sounds particularly unreasonable to me, but would
be interested in any comments on this scenario and options. I am
looking to run the car for another 1-2 years/50-75k miles at least.
Up to $3k repair/year it's still preferable to a new car for me.

I ran into this with my car, a '96 850 GLT. The culprit turned out to be
the "flame trap", which is the functional equivalent of a breather tube. I
found that the trap itself is a round piece of metal, with numerous
passages running lengthwise through it, not unlike a revolver barrel.
Accumulated oily crud will solidify within the passages. It was a simple
affair to use a hand drill with a small bit to cut right through and
eliminate the blockage.

I found that the seal most sensitive was the end of the camshaft, located
at the righthand edge of the engine and held in by three, I think, allen
screws. Very simple to change out (10 minutes) and the seal was
inexpensive - $5.00 from Carquest.

I'd advise making SURE it's not the main seal. I'm told that this is a
common problem with our engines and the remedy is inexpensive and simple.

$1400? Hah!

If it is this seal, you could do it yourself in 30-45 minutes.

However I may exceed this as the Boston roads are leading to at least
one major suspension job per year as well. Ten months after replacing
virtually all the suspension front and rear my new mechanic advises
that control rods are near shot again. I believe him as with the
wheel cranked (e.g. U-turn) I can feel some unnatural play and get
some knocking sounds. I have to say the overall feel of the car on
our rough roads does not inspire a lot of confidence...

My 850 has 274,000+ miles on it and I've had zero problems with the
suspension. Sounds suspect.

On a related note I had a front brake caliper replaced that would
stick after about 1/2hr of driving. Mechanic advised that these
should be replaced in pairs to match hydraulic characteristics, so I
did the other front caliper as well. Does this sound reasonable to
anyone knowledgeable out there?

This sounds ridiculous. I wouldn't believe this; if tolerances varied this
much in production, the market would experience a highly unstable car in
the braking performance department and Consumer Reports, Road & Track, Car
& Driver, Edmunds, etc. would be all over them.

Highly doubtful.

Get the sticking caliper cylinder inspected and possibly honed out. I've
heard of the "piston", which is a small, hockey puck shaped disc to become
somehow lodged at an angle within the bore, causing it to stick.

Like I said the mechanic seemed pretty reasonable (for all I know he's
reading this). I'm just trying to gauge whether I'm sinking too much
money into an aging car.

There are numerous websites to check. Try:

www.volvospeed.com/repairs

or

www.brickboard.com

Thanks in advance for any comments,

ER

Good luck.

 

[Myron Samila]

-

I just switched mechanics and the new service advised me that the main
seal on my '97 850 GLT (107k miles) is leaking. He attributed this to
a partially blocked breather tube, and suggested a short-term
workaround of leaving the dipstick slightly withdrawn to allow
additional air exchange into the motor.

The longer term fix is of course main seal replacement, at about
$1,400USD. Nothing sounds particularly unreasonable to me, but would
be interested in any comments on this scenario and options. I am
looking to run the car for another 1-2 years/50-75k miles at least.

I had the same problem, the transmission must be removed, and this is a big job. It is
common, but the dealer fixed ours for free (just bought the car). The other poster is
mistaken, heeh, it leaks from the rear main seal because of its large diameter, and when
enough pressure builds, this is the easiest seal to blow oil through. It also usually
damages the seal, there is a superceded part number, which makes me believe there is an
upgrade seal as well.

Up to $3k repair/year it's still preferable to a new car for me.
However I may exceed this as the Boston roads are leading to at least
one major suspension job per year as well. Ten months after replacing
virtually all the suspension front and rear my new mechanic advises
that control rods are near shot again. I believe him as with the
wheel cranked (e.g. U-turn) I can feel some unnatural play and get
some knocking sounds. I have to say the overall feel of the car on
our rough roads does not inspire a lot of confidence...

There is a grease point, which is a little surface that the suspension gets limited while
turning (limits the amount of lock to lock position). Make certain there is a small
amount of grease on this little "pad".

On a related note I had a front brake caliper replaced that would
stick after about 1/2hr of driving. Mechanic advised that these
should be replaced in pairs to match hydraulic characteristics, so I
did the other front caliper as well. Does this sound reasonable to
anyone knowledgeable out there?

Typically, calipers should be changed in pairs. I've done otherwise, but I am not
suggesting this. Bleed your brakes first, see what happens after. Make certain any guide
pins or pads are not sticking in the caliper bracket.

 

[G Klein]

Make a few phone calls to verify the cost it sounds on the high side
Were I work labor is 8.0 Hrs we charge $91.00 per hour part usually costs
about $20.00 so shop around before you perform this repair as for leaving
the dipstick out this will not slow down your oil leak from the rear main
seal
Glenn

 

[Dan Behr]

I had the same problem, the transmission must be removed, and this is a big job. It is
common, but the dealer fixed ours for free (just bought the car). The other poster is
mistaken, heeh, it leaks from the rear main seal because of its large diameter, and when
enough pressure builds, this is the easiest seal to blow oil through. It also usually
damages the seal, there is a superceded part number, which makes me believe there is an
upgrade seal as well.

Actually, I'm not mistaken, because that was the problem with my car and what I suggested
solved the problem.

Note I said:

"I'd advise making SURE it's not the main seal. I'm told that this is a
common problem with our engines and the remedy is inexpensive and simple".

The advice still stands.

It's easy to tell - when the engine is running, look around the circumference of the rear
camshaft cover. That's the one with three allen screws/bolts, arranged equidistant around the
circumference of the cover. If you see oil seeping out at any point, you've identified the
problem. Look around for other leaks, as well, to eliminate the rear main seal. At $1400, I'd
be looking hard.

And, I also had a dealer and two other mechanics give me equally huge estimates. I solved the
problem for more than $5.00, but less than $10.00. (Cost of seal, gasket and allen wrench to
right size for the bolt).

Good luck

 

[Eric Raas]

Like I said the mechanic seemed pretty reasonable (for all I know he's

reading this). I'm just trying to gauge whether I'm sinking too much
money into an aging car.

Thanks for all the replies - this gives some useful perspective to the
issues. I will have a look at the seal as suggested, but it sounds
likely the job will need to be done. Will also get a few other
estimates for the price.

ER

 

[Myron Samila]

Actually, I'm not mistaken, because that was the problem with my car and what I suggested
solved the problem.

Note I said:

"I'd advise making SURE it's not the main seal. I'm told that this is a
common problem with our engines and the remedy is inexpensive and simple".

The advice still stands.

It's easy to tell - when the engine is running, look around the circumference of the rear
camshaft cover. That's the one with three allen screws/bolts, arranged equidistant around the
circumference of the cover. If you see oil seeping out at any point, you've identified the
problem. Look around for other leaks, as well, to eliminate the rear main seal. At $1400, I'd
be looking hard.

And, I also had a dealer and two other mechanics give me equally huge estimates. I solved the
problem for more than $5.00, but less than $10.00. (Cost of seal, gasket and allen wrench to
right size for the bolt).

Good luck

What was your simple cheap fix for a oil leak?

The PCV system causes excessive pressure (bad design, either the flame trap on 20V
engines, or the expensive PCV system on the 10V 850 engines), this blows out the rear main
seal.

The easiest way to diagnose it is to look at the weep hole at the bottom of the
transmission, if it is really wet there, and indeed it isn't transmission fluid, it would
be the rear main seal. The rear cam seals could leak, however, diagnosing this
(especially if familiar with Volvo) is easy to do.

Once the seal is damaged, no seal conditioner is going to fix it. It would need
replacing.

 

[Ron /Champ 6]

What is the purpose of the flame trap? What flame? in the crankcase?
in the intake?

What happens if you take it out and leave it out?

What was your simple cheap fix for a oil leak?

The PCV system causes excessive pressure (bad design, either the flame trap on 20V
engines, or the expensive PCV system on the 10V 850 engines), this blows out the rear main
seal.

The easiest way to diagnose it is to look at the weep hole at the bottom of the
transmission, if it is really wet there, and indeed it isn't transmission fluid, it would
be the rear main seal. The rear cam seals could leak, however, diagnosing this
(especially if familiar with Volvo) is easy to do.

Once the seal is damaged, no seal conditioner is going to fix it. It would need
replacing.

Ron/Champ 6

1963 8E5 Champ (Champ 6)
1962 Lark Daytona Convertible (Boomerang)
1995 VW Passat (Vanilla..yuk)
1994 Volvo 850 (Tilley)

 

[Myron Samila]

What is the purpose of the flame trap? What flame? in the crankcase?
in the intake?

What happens if you take it out and leave it out?

The flame trap prevents any crank case fire from going up through the PCV tube. I
wouldn't leave it out, if you have a 20V engine, they are just simply a small little unit
that either can be replaced or cleaned.

On the 10V (at least the one I have) requires quite a few parts when replacing the PCV
system, with labour at the dealer, it was $450 Cnd (done by the previous owner AT the
suggested interval). Shortly after we bought the car, (1 week), the rear main seal made a
huge mess on the garage floor, it had collected inside the transmission bellhousing.

Do a google search for Volvo flame trap and see what happens

http://www.swedishbricks.net/faq/flametrap.html

 

[Jeff Lesperance]

Eric:

I would not leave the dipstick tube out of place at all. Oil can and will
find its way out of it, and will at least make a mess and possibly leave you
very low on oil. The breather tube is the flame trap, you can see more
about it at www.volvospeed.com in the repairs/maint. section.

I was quoted about 900 to have mine replaced (95 850 GLT, 153,000 miles). I
would price around before plunging. I have a small leak, so I tried a
bottle of stop leak, and about 1000 miles later, no or very little dripping.
Its a short term thing, but I wanted to try it. I am surprised your
suspension is wearing so fast. I live in metro detroit, and our roads are
super ultra bad.

I replaced one caliper in the front due a torn piston boot, and have had no
problems. I even went about 100,000 miles before getting an alignment, only
because I had the control arms replaced (1st set).

I would check out www.brickboard.com or www.swedespeed.com for more info.

Jeff

 

[Jim Carriere]

What is the purpose of the flame trap? What flame? in the crankcase?
in the intake?

The flame trap is supposed to keep the flame from an intake backfire from
finding it's way into the crankcase, because the oil mist and air in the
crankcase could be explosive.

This isn't to say your engine could blow up like a mafia car bomb from one
backfire, but I bet you would be looking at all new seals.

I have a mixed opinion how important it really is anymore. I maintain the
flametrap on my own car, but how often does a modern engine backfire?

Anyway, engine backfires usually happen for either of two reasons-

1) extremely lean a mixture, does not burn properly and the flame sometimes
finds it's way back through the intake. The concussion from an intake
backfire may even be felt by your foot on the gas pedal.

2) "trailing throttle," which is when you lift off the gas pedal at high
rpm, combustion can be irregular because the engine is running at an awkward
load/mixture/spark advance setting. This isn't exactly true in modern
computer controlled fuel injected engines- most if not all Volvos for the
last 10-15 years shut off fuel above about 1500rpm. In engines that do not
have this feature, a burbling sound can be heard in the exhaust pipes during
engine braking. Obviously the flame trap has nothing to do with this...

 

[Dan Behr]

What was your simple cheap fix for a oil leak?

The cheap, simple fix in my case was as described above. I was fortunate that it was only the
camshaft rear cover seal.

However, the cause was the same - internal pressure built up, because the flame trap was
clogged.

 

[Doug Warner]

I replaced one caliper in the front due a torn piston boot, and have hadno
problems. I even went about 100,000 miles before getting an alignment, only
because I had the control arms replaced (1st set).

Why did you replace the caliper? The rebuild kit, which contains all
the rubber bits is fairly cheap..

To reply, please remove one letter from each side of "@"
Spammers are VERMIN. Please kill them all.

 

[Stephen M. Henning]

Anyway, engine backfires usually happen for either of two reasons-

Another is if the timing belt slips or is put on wrong.