1996 850 Sudden Oil Consumption

Our 1996 850 GLT wagon, wtih 75,000 miles, has had regular oil changes and
never indicated any drop in oil level between changes.

Shortly after an oil change, two months ago, the oil light came on on the
dash and it was 2 quarts low. I topped it up and watched it closely. Since
then, in the past two months, it's taken another 5 quarts (one every couple
of weeks).

The underside of the engine is clean and dry, no drips or leaks.

If it were something horribly wrong with the engine (rings?) I'd expect the
exhaust to be black and smelly, but it's not. Also, the OBD hasn't
indicated any faults.

What should I look at next?

Thanks, as always, in advance,

-RL

p.s. This is not the 850 with the bad transmission, this is our *good* car.

 

It is reasonably common for the valves in this engine to pit and then
for a small hole to burn through. This will result in considerable oil
consumption. I know several 850s that consume about 1 quart of oil
every 1000 miles.

Since an entire valve job is expensive, my usual recommendation is for
the owner to decide how much longer they plan to own their 850s, and
then determine whether it is worth their while to spend ~$1500 to fix
the problem. Otherwise just keep topping off the oil ever so often.

Although with your car the oil consumption seems to be (quart every
500 miles?), my guess is that it is the same problem. If you plan to
keep your car another 75,000 miles, get it fixed. If you don't,
don't bother. If you do get it fixed, keep in mind that in addition
to the valve job, the car will need plugs, wires, distributor cap
to be replaced around 90,000 miles, and timing belt, tensioner and
water-pump at 140,000, and the cost of this maintenance might be
important for your decision.

Beverly

 

Thanks for your reply.

How would I verify that a valve pinhole is the problem before undertaking a
valve job?
Would I see it from the top if I took of the valve cover?
Is there a particular signature in the exhaust emmissions to indicate oil in
the mix?

I'd suffer the expense if necessary. Probably even seek out a
Volvo-certified mechanic to do it.

I always expect my Volvos to last for 250 Kmiles. Sometimes they even do,
but never without the occasional $1500 repair. I just want to make sure
that it's really the problem. I've only needed a valve replacement once
before, on my 264 GL at 200 Kmiles. Did it myself that time.

Thanks again,

 

Looking at the spark plug tips and a compression test will tell you just
about everything you need to know. It's amazing how much oil an engine
can burn without leaving a cloud of smoke. I had a '74 145e that I'd
need to fill with oil before gas, and there was never any smoke at all
behind it.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Oil consumption does not always result in an exhaust pipe mess. I
would try a couple of simple things. First, I would try,with a well
warmed up engine, driving along at about 50-60 mph, releasing the gas
pedal and coasting down to about 10-15 mph slower. Then step abruptly
on the gas, while looking in the rear view mirror for a telltale puff
of smoke. That would indicate that oil is getting past a bad piston
ring.
The other thing to do is to have a mechanic perform a simple
compression test. If there is a low cylinder, you can be fairly
certain there is a damaged valve or ring in that cylinder.

 

What oil is the mechanic using his favourite brand (most profit ) or a
quality synthetic oil .My friend drove his old Japanese car a few hundred
miles to visit us and the car was low on oil .He was suprised as normally
he didn't use oil .But also the car never went on long runs so the hot run
burned off the moisture and the cheap junk oil he was using .I topped it up
with BP or Mobil synthetic and on his return no oil was used at all .Junk in
junk out as the lower fractions of oil burn off as well the moisture burns
off , not so with synthetic .In other words cheap oil is risky and you use
more but synthetic is more expensive but you don't use much in top ups .

 

Oil doesn't burn off. It carbonizes and becomes a molasses like
substance which is almost impossible to get out. If you use ordinary
motor oil in air-cooled engines in very hot weather you will discover
this quite quickly. To avoid this, I use motorcycle oil in my
air-cooled engines. It is formulated for very hot use.

Did you really think that a small amount of synthetic is going to make
the other 4 quarts of regular motor oil not do what it was doing before.
I think not. Otherwise, why not just use 90% cheap oil and 10%
synthetic.

I saw the same weird use of oil happen once in a friends Dodge. It was
speed dependent. Above a certain speed the engine blew or burned oil.
Below that nothing happened. He was in a big hurry going from PA to NM
and carried and used oil in bulk. On the return trip, he took time to
smell the daisies and didn't use any oil. That sounds more plausible.

 

actually the lighter fractions of oil do burn off and yes the 3 litres I put
in did make a huge difference 75 %synthetic to one litre of cheap oil made a
huge difference as well moisture builds up in oil and burns off when the oil
get good and hot so the level of oil drops .I must admit I also tuned his
car till it ran sweet .It all helps .
As we have turbos we only use Synthetic can afford to use "cheap oil" its
expensive in the long run .

 

You are saying that the car was 3 litres low on oil and the engine was
still running. I don't believe you. Have you tried contacting the
guiness world book of records. I think they will put yours in the
whoppers section. I still think you had a speed related problem that
was either blowing the oil out or leaking it. Telling such whoppers
won't change my mind. How long is your nose.

 

It does depend on the size of the oil reservoir in the old Japanese car
in question. That being said, the most I've seen _car_ engines take is
about 7 - 8 quarts of oil, which is about the same as 7 - 8 liters of oil.

On an 850, losing 3 quarts of oil would certainly damage the engine. I
think the reservoir is between 6 - 7 quarts.

Beverly

 

He said that 3 litres was 75% of the capacity.

 

Hi.

Remember me? I'm the one who started this slugfest. Well, at the risk of
prolonging the discussion (which long ago diverged from addressing my
problem), here's a little info I left out the first time:

Historically, we've always had our mechanic, who only uses Quaker State,
change the oil. This last time, we were in a hurry, on our way out of town,
so we had it changed at Jiffy Lube. Naturally, when the light came on, I
figured they had cross-threaded the oil plug, or the filter, but it's not
dripping anywhere.

Perhaps the quality of Jiffy Lube oil IS an issue here.

At this point, though, I've added 6 quarts over two months, so it's likely
had a near complete transfusion.

We have an appointment with the Volvo dealer next Wednesday. Stay tuned...

 

Well, after two weeks wait, we finally came up on our appointment at the
local Volvo dealership. I was giddy with excitement at the prospect of
having a real Volvo-certified technician diagnose the oil consumption
problem on our 1996 850 GLT wagon.

When I dropped off the car, I told the kindly service representative what I
knew: 5 quarts in 6 weeks and 1000 miles, no sign of leak or drip, no
obvious smoke from the exhaust. He promised to perform the official Volvo
"Oil Consumption Test Protocol." I asked whether that included compression
and vacuum test and he assured me that they would check all aspects of
engine function.

So, when I picked it up, 8 hours and $240 later, the kindly service
representative reports to me that they changed the oil and that it is not
leaking. I asked:

"Did you check the compression?" No.
"Did you check vacuum under load?" No.
"Did you check the exhaust on a gas analyzer?" No.
"Did you removed the valve cover and inspect the valves and seals?" No.

"Well, what exactly did you do?" We changed the oil, checked for leaks, and
verified that it runs o.k. The next step is for you to bring it back every
two weeks so we can determine the burn rate.

I'm largely unimpressed with the Volvo "Oil Consumption Test Protocol." I
regret not forcing the issue of what exactly the protocol includes prior to
leaving the car with them. I regret assuming that the certified Volvo
technicians with all their experience, knowledge, and fancy tools were the
experts. Note that this is not the first time the dealer service department
has turned out to be expensive and useless. I'm not surprised by their
incompetence, just disappointed.

On the lighter side, their service department is quite clean, friendly, and
provides free coffee in the waiting area so, really, I have no cause for
complaint. Oh wait, nix that, they didn't even try to fix the car.

Now two more weeks have passed and our long-drive vacation is only two weeks
away. I'm guessing the next step is to buy myself a compression gauge and
examine the spark plugs. Any chance I'll observe something by removing the
valve cover, or do I have to dismantle the head to see if the valves are
pitted?

-RL

 

Ouch! The Volvo dealership we use doesn't charge for the oil consumption
test as described above (besides the oil change -- total cost $39.52,
including labor). The instructions are to drive the car for 1000 miles
after the change, and bring it back in to be measured again.

 

Usually my Volvo dealer puts some tracers in the oil or uses oil with
tracers that make it easy to find the leak. That may cost a little
more, but not $200. Most of the time they can find the problem just
upon inspection without doing this. It sounds like the other dealer
came up with a test that just extracts money from the customer's wallet.