dirty oil can stretch timing chain?

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I noticed a current thread on an automotive forum in which the customer brought in their 09 car due to a check engine light. The customer was told that the reason for the light was a malfunctioning oil life sensor. (The car showed 10% on the GM OLM with an OCI of 12k miles). Furthermore they said this oil was dirty enough that it caused the timing chain to stretch and would of course need to be replaced.

Is this scenario possible?
 
Not possible.
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No GM product has a oil SENSOR.

Its all computer reading other sensors that are REQUIRED by the ECM to run the vehicle. If any of those sensors has a problem, check engine light would have been on.

Oil that is spent will cause the timing chain to wear quicker.

Bill
 
Originally Posted By: Bill in Utah
Not possible.
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No GM product has a oil SENSOR.

Its all computer reading other sensors that are REQUIRED by the ECM to run the vehicle. If any of those sensors has a problem, check engine light would have been on.

Oil that is spent will cause the timing chain to wear quicker.

Bill


Yes but dirty oil will not stretch a timing chain. That is the silliest thing I have ever heard. Timing chains will last darn near forever, it's the tensioners you usually have to watch out for, and I doubt that's what the problem was seeing as they replaced the chain.
 
Originally Posted By: simple_gifts
Quote:

Uhhhhhhh.... What? Most ridiculous thing I have ever heard in my life.


Have you read the MMO threads?


Good one
 
Originally Posted By: simple_gifts
Quote:

Uhhhhhhh.... What? Most ridiculous thing I have ever heard in my life.


Have you read the MMO threads?

Someone ------- in your Cheerios this morning?
 
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Dirty oil will not stretch a timing chain in a GM vehicle. Most have a double roller chain with a mechanical tension adjuster. going a few miles over the limit would not cause a chain to stretch. 300,000 miles, the chain might stretch, but not from going a 1-3k over the OCI. That is my opinion. I would say take to a good independent mechanic and get their opinion.
 
It sounds like the dealers service dept is trying to pull a fast one on warranty repair.The car would probably get an oil change then get parked up for a few days.
The dealer would then declare the car all set and have the customer sign off on it then bill GM for extensive repairs.

Par for the course,happens every day.
 
Originally Posted By: rudolphna
Originally Posted By: Bill in Utah
Not possible.
31.gif


No GM product has a oil SENSOR.

Its all computer reading other sensors that are REQUIRED by the ECM to run the vehicle. If any of those sensors has a problem, check engine light would have been on.

Oil that is spent will cause the timing chain to wear quicker.

Bill


Yes but dirty oil will not stretch a timing chain. That is the silliest thing I have ever heard. Timing chains will last darn near forever, it's the tensioners you usually have to watch out for, and I doubt that's what the problem was seeing as they replaced the chain.


Notice that I used the word SPENT. If the oil is not lubricating it will cause wear on a roller chain. Seen it on a engine that had a head gasket leak with coolant in the oil.

Bill
 
correct, timing chains "stretch" by wearing. also true that there is no such thing (yet, not in a GM) as an oil life sensor. the oil life is calculated based on a algorythem of temperature, miles, starts, engine load, etc....
 
I used to work at Suzuki dealership and the last XL-7 had trouble with chain stretch and was a known issue. It was a GM engine down to the GM emissions sticker.

GM junk
 
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Originally Posted By: Steve S
Actually chains do not stretch they wear, which increases the chains length.


+1,Good oil is esential for OHC chains and guides. As Bill said, if an oil is spent wear can occur with the rollers and cause the chain to lengthen.
 
A car that's barely one year old with a stretched timing chain because the customer went 12k on the oil? Horse-hockey. If the chain really WAS bad, it was factory defective.
 
Originally Posted By: RF Overlord
A car that's barely one year old with a stretched timing chain because the customer went 12k on the oil? Horse-hockey. If the chain really WAS bad, it was factory defective.


Sorry didn't notice the 12,000 mile detail. You are right under those miles. Chain wear is more of a high mileage issue.
 
Dirty and I do mean really nasty oil will wear out other more crucial parts in an engine well before the chain is affected.
 
Scenario came down like this: Customer came in for OLM indicated oil change. Homer saw that it was 12k and went "Shezzzzzaeem!!
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"The OLM must be broken!! Anyone knows you need Mobile 1 or AMSRoyal to go that far!!".
 
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