Have got an 05 liberty crd that only has about 63,000 miles on it. It runs and drives great. I am new to the light diesel world But it seems to have a fair amount of blow by. Im not sure if that is normal for these motors or not. It has the GDE eco tune since about 9000 miles according to the last owner and has had the pcv re routed since about the same. I run Rotella T6 in it because thats what he ran. Can anyone else chime in on this? Anyone use lucas heavy duty oil stabilizer in their CRD's? Also can you mix that stuff with pure synthetic oil?

Thanks,

Diesels typically have a lot more blowby than gas engines for one very simple reason: gas compression ratio is usually in the 8-10 to 1 range, whereas diesels are usually in the 16-22 to 1 range. This creates very much higher pressures in the cylinders, and more blowby is the inevitable result. And while the CRD's compression ratio is only 16.5 to 1, yes, it will have a lot more blowby than someone used to gassers will expect. Fugedaboudit. Not to Worry, it is normal.

I know nothing about Lucas products. Stick to straight T6 or Mobil TDT or Mobil 1 0w-40 and you don't need any magic oil additives.

Given that your new ride has only 63,000 miles on it, and the official distance for the required timing belt replacement is 100,000 miles, I suspect yours is still the timing belt it came with. But that timing belt is rubber, and is now 8 years old. I (and many others here) would recommend you spring for an early timing belt job, just on the theory that old rubber is bound to have deteriorated, and you do NOT want that belt breaking on you. That way lies some very, very expensive repairs.

I sounds you'll be a happy owner with the set up you have. I wouldn't mess with magic additives that will cause you headaches later, keep your Rotella oil changes every 6k miles and enjoy.

Roger that. Although I am new to the liberty I have had an 06 duramax that ive done a bunch to since 08. This thing runs about the same compression 16.8:1 and has 1/4 of the blowby that this jeep has. My guess is the tolerances are just much better. Thanks for the input though and I'll just stick to T6 and not worry. Its the wifes car so I made a pcv catch can/filter this weekend. Same setup I've been using on the duramax for years now and Ill see if that helps with the visible oil vapor/fog she sees. As for the timing belt, probably a good idea. Ill get the parts ordered up here soon and start planning to do it. Whats a good source for the parts and or kit? I know GDE rents the tool but wasnt sure if they offered anything else.

Thanks again

In theory...
There should be almost zero blowby while driving under load. Cylinder pressures would be much
higher under load which should force the compression rings into a tighter seal in the cylider.
I dont know how to verify that however, but it makes sense to me.

At idle, cylinder pressures are lower and therefore more visible blowby.

While idling and cold, I see no blowby from my engine.
I notice the most EHM smoke while hot and stopped at a light, after having been driving for
a while.

_________________
U.S. Army Retired

agreed, I see a small amount when cold and idle. It increases when hot at idle with a little load on the engine, like a.c. or something. The oil stays very clean so its not a huge concern or anything just much more than the 8 cyl duramax. Anyone have any experience with the longevity of these motors? Also, what kind of boost are they running? My guess would be somewhere around 4 lbs average highway driving and maybe 15-20psi max?

Stated blow by is normal with CRD's. Do not use any oil additives. They have been proven to do more damage than good. Installing a PROVENT will trap oil and keep you from smelling anything. But there are lots of CRD's eating oil with no negative effects after the EGR is stopped. Watch venting to the rear due to the system will freeze up and cause oil leaks. Sometimes less is best.


I don't know where you live, but here in PA winter is cold. Using OEM Suggested 0w-40 will be best for cold starting and protection.

FYI...if your timing belt has not been changed? Its needed even at only 63k

Good luck,
KJJET

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05 Liberty CRD Sport with Leather 115k
GDE ECO, No EGR, no FCV, (system gone)
Oil Drain plug P/N 090-039
K&N Air Filter, 2nd gen Fuel filter head
NEW Rockers & lifters
Mobil 1 0w-40
Stant 13519 195 deg inline Thermostat.
0 281 002 845 MAP
Etecno GX3123 7v Glow Plugs
Advance Gold 800CCA Battery
Traded it for a Quality VW TDI

_________________
05 Liberty CRD Sport with Leather 115k
GDE ECO, No EGR, no FCV, (system gone)
Oil Drain plug P/N 090-039
K&N Air Filter, 2nd gen Fuel filter head
NEW Rockers & lifters
Mobil 1 0w-40
Stant 13519 195 deg inline Thermostat.
0 281 002 845 MAP
Etecno GX3123 7v Glow Plugs
Advance Gold 800CCA Battery
Traded it for a Quality VW TDI

2005 was the first time anyone in the US had seen these engines on the road.
A few people have checked in here to say have 200K miles already.
I'd say most on this forum are between 100K and 150K miles.

The highest boost I've seen is 23 psi, but I've never really floored it.
At 70 mph I think I'm at about 6 or 7 psi on flat road.

_________________
U.S. Army Retired

ok great to hear that its normal. Ill get on that timing belt asap then, dont want to have that sucker break on my wife she would not be happy. Good to know on the boost, about what I was thinking.