Big Oil Leak front of 2.5T - Two cam seals and front crank seal - Any other seals ?

waid302 · Post by **waid302** » 13 Nov 2019, 16:53

Achilles wrote: 13 Nov 2019, 05:35 Make sure you check the charge air hose. It gets saturated with oil as well it’s a quick fix to replace and will leave you stranded if it bursts from oil saturation.

Which hose is that? Pipe from inter cooler to intake ?

Achilles wrote: 13 Nov 2019, 05:35 With the engine running pull the dip stick or the oil filler cap. If there is much resistance from vacuum then you have a bad oil trap replace it or you’ll be doing the cam seals again.

I put a rubber glove on the oil filler and had good suction. I though this was good. I am confused. Please explain. Normally you will get little bit blow by when oil cap is opened on most motors - positive pressure so seeing vacuum on Volvo is puzzling to me.

Thank you

Waid

Achilles · Post by **Achilles** » 13 Nov 2019, 17:20

Well on the 2.5T the vacuum should be between -0,1and -0,5 kPa At the cap and or the oil dipstick tube. This is an extremely low amount of vacuum. I have to use a special Volvo vacuum gauge to measure it because a standard vacuum gauge will barely move at this pressure. Sometimes when the oil trap fails it shows no vacuum but most of the time in the 2.5T when it fails is pulls excessive vacuum. You’ll hear a “whoosh” when you remove the oil cap on an idling engine at operating temp and that’s a good indicator of excess vacuum. I have replaced cam seals on this engine maybe 30 or 40 times and the vast majority, like estimating 95%, of them have excessive vacuum indicating a clogged oil trap (PCV). Vacuum on this engine doesn’t fall within what we are used to on most other brands. It is something I had to get used to when I became a Volvo technician. The charge air hose is the one in the front of the engine between the inner cooler and the intake. Other symptoms of a clogged oil trap are oil leaking from the turbo and an oil saturated charge air hose.

waid302 · Post by **waid302** » 14 Nov 2019, 06:22

Achilles wrote: 13 Nov 2019, 17:20 Well on the 2.5T the vacuum should be between -0,1and -0,5 kPa At the cap and or the oil dipstick tube. This is an extremely low amount of vacuum. I have to use a special Volvo vacuum gauge to measure it because a standard vacuum gauge will barely move at this pressure. Sometimes when the oil trap fails it shows no vacuum but most of the time in the 2.5T when it fails is pulls excessive vacuum. You’ll hear a “whoosh” when you remove the oil cap on an idling engine at operating temp and that’s a good indicator of excess vacuum. I have replaced cam seals on this engine maybe 30 or 40 times and the vast majority, like estimating 95%, of them have excessive vacuum indicating a clogged oil trap (PCV). Vacuum on this engine doesn’t fall within what we are used to on most other brands. It is something I had to get used to when I became a Volvo technician. The charge air hose is the one in the front of the engine between the inner cooler and the intake. Other symptoms of a clogged oil trap are oil leaking from the turbo and an oil saturated charge air hose.

Great info Achilles,

Dumb question. Wouldn't I be able to blow on this pipe to see if the oil trap/hoses are plugged ?

I have rebuilt motors before so take the intake apart does not scare me. With 160,000 miles, the PCV is probably plugged along with bad VVT gear.

Thank you so much!

Waid

Achilles · Post by **Achilles** » 14 Nov 2019, 06:33

There are a few potential problems. That hose is usually replaced as part of the process because it is hardened usually but not clogged. The diaphragm in the oil trap is one usual failed part and the nipple that attaches beneath the intake is usually clogged. It’s probably hardened by now and most likely will break when the intake is removed. So that needs to be replaced regardless. Also there is likely build up in the block outlet behind the oil trap that needs to be chipped out until you can blow compressed air through it and feel the air blow through the oil filler. I usually use a wire hanger to chip it out it curves down into the oil pan. This is a step even professional technicians often miss. Then they wonder why they continue to replace oil traps.

waid302 · Post by **waid302** » 14 Nov 2019, 07:11

Achilles,

From previous post here, the high-mileage VVT walks in and out, causing the timing belt to "walk". You can clearly see the timing belt walking the exhaust side (back side). I am going to check how much play I have in my VVT this weekend.

Therefore, the VVT is bad or starting go bad and causing oil leak?

Should I replace the PCV first and see if there are any leaks later or just go ahead and VVT gear and PCV now?

Thanks

Waid

Achilles · Post by **Achilles** » 14 Nov 2019, 08:24

It very well could be the VVT causing the leak and the belt to walk. other possible causes could be the tensioner. I would first check the oil trap for correct vacuum at the oil dipstick tube, then check the timing tensioner. If the oil trap checks out and the tensioner springs back appropriately then change the VVT. While you are in there I would replace both cam seals regardless of what you find to be the problem. Also change the timing belt, tensioner and pulley. The oil saturation on these components can cause premature failure on any and all of these components. And that failure results in valves or at worst an engine replacement. At $100 a valve either way it’s an expensive fix. So no matter how you slice it, to do it right, you’ll need to replace the timing belt pulley and tensioner and both cam seals the only question is the oil trap and VVT.

waid302 · Post by **waid302** » 14 Nov 2019, 08:45

Achilles wrote: 14 Nov 2019, 08:24 other possible causes could be the tensioner.

Why would tensioner cause a leak?

Is the cam gear closes to the firewall the exhaust cam gear?

In your experience, does the intake cam gear can also go bad and also cause oil leak ?

Thanks

Waid

waid302 · Post by **waid302** » 17 Nov 2019, 18:36

Took my PCV catch can out today and it was actually pretty clean. This was not the source of my problem! With little carb cleaner, I was able to clean it up really good. The PCV can was also in really good shape and I am soaking it while I wait for new rubber hoses. I will re-use the catch can. Went to junk yard and got 2 intake and 2 exhaust VVT gears at $6 each. They have very little play and there were no leaks on the two motor that I pulled them from. For $6 each, I am willing to try used ones with new o-rings! I will replace the intake and exhaust cam seals along with oily timing belt.

I have another problem. I had a small leak on my Thermostat Housing so I removed the two bolts. It looks like 2.5T uses two piece Thermostat Housing and I am not finding gasket any where.

Is the inner gasket for Thermostat Housing available anywhere at all?

If not, will just use good old RTV.

Waid

Post by **cn90** » 19 Nov 2019, 22:01

- Re thermostat leak, 2 options:

1. Get a new thermostat assembly and replace both the thermostat and ECT w/o the need to remove the PS Pump.
I posted detailed DIY for thermostat in forum:
viewtopic.php?f=10&t=79031

2. Get generic paper gasket from local auto parts store and cut a paper gasket yourself.
The generic paper gasket is very cheap. Just cut a template to follow the upper tstat housing.
Make sure the holes are drilled in the correct places.
There is a youtube video somewhere...

waid302 · Post by **waid302** » 21 Nov 2019, 10:39

I ended up using RTV from Permatex specifically formulated for Thermostat Housings. I have used RTV many times in the past and never had any issues.