Greetings All,

I apologize if I'm not using the proper names for parts and for how long this thread is.

10 days ago I noticed coolant leaking from the bottom of my 2003 LB7. Thought it might be a hose so I attempted to remove the hose I thought was the problem but even with the clamp completely off the hose wouldn't budge...
Not having the time or a garage to deal with this I took the truck to my local Chevy dealer to have them check it out and the power steering pump which was making some noise. Since it was about time for an oil change I had them take care of that too. $1700 later I had a new water pump, power steering pump and oil change. I was broke but my truck running like new. Life was good!
A few days later I noticed smoke coming from the front of the truck. When I got home I looked under the truck and noticed exhaust (It smelled like burnt diesel) coming from a "hose". It looked like the hose had been connected to something as the bottom 3 inches was clean but the rest of the hose had some road grime on it. I couldn't find where the hose belonged so I took it back to the dealer the next day. No one had a clue what might be wrong (one mechanic also noticed the "clean area" on the hose) with it until they got the "Diesel Mechanic" to look at it.
The first thing out off his mouth was the injectors where bad an needed replacing. I was relieved as this same dealership had changed the injectors in December 2014 and I assumed there was some kind of warranty on the new ones. When I told them the injectors had just been replaced by them, I thought the Service Manager was going to have a stroke. Of course the diagnoses changed immediately...

Long story short, they've had it for over a week now and they want to do an internal inspection to see if there is a problem with pistons and / or rings.

Here are some facts.

When I was checking for the coolant leak I had the engine running and saw no exhaust / smoke coming from anywhere in the engine compartment.
No "Check Engine" light went off. All my gauges were normal except the engine temp which was a bit cooler than before the water pump was changed. There was no change in the sound of the engine before or after the dealers service. Coolant and oil level were both normal. Oil color was what I would expect after having been changed a few days prior. The truck started / idled / and ran normal before and after I picked it up, excepting the smoke of course.

I'm not all that confident in this service department as a number of hoses and wires were found unconnected after they serviced the injectors...In the past they serviced my truck quoted me a price over the phone and doubled the price when I showed up to pick up the truck.

Here are my questions.

What are the odds that the rings would start showing wear right after the water pump was serviced and the oil was changed?
Wouldn't a simple compression test give some indication of a piston / ring issue?
If a piston was bad wouldn't the engine "sound" different, "run" different?
What questions should I ask before letting them do the "internal diagnostic"
My brother-in-law told me a lighter weight oil would show similar symptoms, how true is that?

I love my truck, in 12 years and over 175,000 miles it's never left me stranded. But I've spent over $10,000 on this engine in the last year and don't want to be taken for another ride by the dealer or spent more $$$ and have the engine die two weeks from now!

Any advice / help would be appreciated!

Confused in Connecticut!

 

they can do a compression test, or you can do it yourself as well with a 15 dollar kit from habror freight and a free afternoon. really nothing from the oil change or water pump operation would cause the rings to fail. it does have 175k but thats not very many miles. does it stlll smoke?

 

The dealer still has the truck so I will assume it still smokes. I was told that "an engineer" wants to do an "internal inspection" on the pistons and rings but that's not their final diagnoses.
It just pisses me off that the engine didn't smoke until they did service on it.

Feels like a scam...

 

i mean, they can compression test and perform a cyl leakdown test. thats all really they can do besided look at the oil for diesel in it.

 

Generally if you have any kind of smoke coming from the crank case in a diesel it's due to "blow by" unless it has a crank case ventilation system and it's not functioning properly. Changing the oil , drains all the oil from the engine and depending how long they let it drain before starting it up after the fill could potentially cause the cylinder walls to dry. Therefore upon start up and no oil press on dry cylinders and a cold tight engine will wear rings very quickly. Or!!! That the oil change kids drained it and didn't fill it and ran it for who knows how long before realizing nobody filled it up, or put the wrong filter on it amd ran it with no oil press for who knows how long before seeing it had no pressure. There's just alot of what ifs in these situations with absolutely no way to prove anything. That's why I don't let anyone work on my truck! People are way way too Hard to trust anymore to accept responsibility for there stupidity anymore , they just tend to blame it on someone else. Usually the customer , as they generally don't know any better. They assume because there not working on there own vehicle that they can fool them with false logic just to get in there wallet. It's very hard to find a solid shop/mechanic anymore.

 

what about doing a balance rate test? if it did have some bad rings/cylinders then those numbers would be high, that is of course assuming the injectors are still good.

if you take off the oil fill cap does it blow out smoke there?

 

I had the same problem I replaced the injectors myself bought from Lincoln Diesel also replaced the PVC valve located on the valve covers and next to the vent tube no more smoke! run great!