smoke from diptick

[allformike]

i noticed today my truck had smoke coming out of the dipstick, is this bad.:confused:

[mr. monte]

I would say "blow-by"

so I would guess that your rings/cylinders are getting worn

[Robyn]

All these engines generate some blowby. The issue is how much.
If the engine is idleing with the oil fill cap off a small amount of vapor coming from the filler is normal on an engine with a fair amount of time on the clock.

I rise of RPM to about 1000 should see this go away. If it does not go away or gets worse with RPM then it may be other issues.

A small amount of vapor is normal and you may want to check the CDR valve. This is the little can assembly that either connects to the RH valve cover and then to the manifold or the oil filler and the manifold.

This will depend on the year and model of the truck.

Now if you remove the oil filler cap and there is a lot of smoke puffing out then it may well be more serious such as a hole in a piston, bad rings ect.

let us know

Robyn

[Mark Rinker]

After swapping in a 60K mile 6.5L into my '94 K3500, I started burning a quart of oil every 1500 miles, and had lots of oil vapor present when the oil fill cap was off.

Changed from Rotella to a quality brand synthetic oil, replaced the CDR, and watched the oil consumption subside, mileage increase, and vapor at the fill tube diminish by 50%.

It might not be your rings, it might just be the oil you are using isn't up to task.

[Robyn]

Mark
Interesting you should mention Rotella. I have used that and Delo-400 for years in the big rig and in the 6.2 and 6.5's and had great results.
I have used the Amzoil synthetic but stopped as the cost and availability issues just made it tough to get and to justify the cost.

Some of these engines are no doubt seeing non diesel service motor oil being used too and certainly can contribute to the issue.
I was recently involved in a rebuild on a 6.5 from a 2000 GMC
The sucker had been run with 5-30 motor oil (Gasser rating) and the rings were mostly all stuck tight in the grooves.

We hauled the pistons out and freeded the rings up and then actually stuffed the little monster back together with just new gaskets and some incidentals. Runs fine now.

Very low mile engine with a lot of sitting time.

Interesting

Robyn

[Mark Rinker]

I know that many here run Rotella and have good results. I switched after Bill Heath told me he had "...given up on trying to keep Rotella in his 6.5s - too much oil consumption'. Maybe that indicates that it had something to do with higher fuel rates and boost pressures - or Bill's tune which I was running on the truck...? Certainly too high boost pressures can cause to excessive blow-by!

In retrospect, I also turned the boost down at that time, which also might have been a factor, to about 8-10psi average, from about 10-12psi average at cruise speeds, loaded with trailer.

The CDR may have been the culprit all by itself. Either way, one or a combination of all of these changes seemed to reduce the excessive oil vapor I was seeing in the crankcase on my 6.5.

Hope this helps!

[93GMCSierra]

I believe the CDR to be the real difference I have seen that in my truck as well.

[allformike]

there isn't very much coming from the oil fill neck. oh ya and it's a 89 k2500, 6.2 n/a

[IUPAC]

I purchased a project 6.5td truck from a member last year that ran great. After getting it home and tinkering with it before I pulled the motor I noticed blow-by puffing from the dipstick tube. I hoped it was just the rings. It kind of was.... the rings couldn't seal the gap left by a crack in the rear wall of #7 cylinder. Anyone need a boat anchor?

[HH]

You may want to do a compression check. Mine was doing the same thing, and eventually oil was coming our the dip stick tube. The reason....cracked #2 piston. Hope it is just wear.