1998 GMC Sierra, Mobil 1 5w-30 first UOA.

[sm]

This is my first UOA and i hope to receive some feedback from the results.
Truck is a 98 GMC Sierra 4x4 with 5.7L.
Truck had 191015km at sample date.5038km on oil and filter. Oh and oil was in service from Sept 25/04 to March 25/05. Lots of short trip winter driving in southwestern Ontario. The analysis was done by Wearcheck.
Now the numbers....

Silicon 13
Potassium 90
Sodium 13
Fuel % Glycol Pos
Water % Soot -
Sulfation 77
Nitration 67

Boron 124 Base 94
Barium 0.2 / 0.0
Calcium 2550 / 820
Magnesium 116 / 1388
Moly 63 / 0.0
Sodium 13 / 0.0
Phosphorus 815/ 720
Sulpher 1769 / 2240
Zinc 943 / 780
Visc @100*C 10.1 / 9.9
Oxidation 76
Tan -
TBN 5.95

Iron 11 Abn 150
Nickel 0.2 / 5
Chromium 1.4 / 20
Titanium 0.0
Copper 3.1 / 155
Aluminum 3.7 / 40
Tin 1.2 / 10
Lead 3.2 / 50
Silver 0.2 / 2

Wearchecks` comments are as follows;
" Although the glycol test was pos. other chemicals other than antifreeze can cause a similar reaction including the oil additive package, or supplemental oil additives. As there is insufficient evidence such as high wear metals, or the presence of water to indicate a serious leak, no other maintaince actions, aside from those recommended here should be carried out at this time. We reccomend you drain the oil from the component if this has not already been done. Check for low coolant level. We reccommend an early resample to confirm this situation,however a minumum of 10 hours, 500 miles or 800km on the oil is required before resampling to prevent a false glycol reactions that can be experienced with new oil.

After the sample was taken i changed oil and filter with a fresh fill of XD3 0w-30. I also have an appointment next friday 29 to have the leak repaired ; i think it is the dreaded intake gasket leak. Did i leave any information out that could help??
Comments and suggestions welcome and thanks to everyone for a great forum!!
Steve

 

[Triple_Se7en]

Why did you quit using the 5W-30 Mobil-1? You probably experienced some increased oil usage with it, but that's attributed mostly to coating - common with 1st time Mobil-1 use in older engines.

 

[Al]

quote:

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Originally posted by Triple_Se7en:
Why did you quit using the 5W-30 Mobil-1? You probably experienced some increased oil usage with it, but that's attributed mostly to coating - common with 1st time Mobil-1 use in older engines.

---

He plans on keeping the oil in there for only a few hundred miles and then resampling.

The wear numbers were very decent. Potassium + the pos test for glycol does indicate a problem. Mobil 1 doesn't have potassium. The problem with sampling in only 5oo miles is that you could either have 20% or so of old oil remaining and therefore will have a 15 to 20 ppm potassium and probably a pos test for glycol. You should dump this oil and put in new unless you already did a flush.

 

[sm]

Triple Se7en- went with the XD3 just to try something new. Actually oil consumption was nil;no top up added. Have been using syn in the truck for the last 85,000km; but this was my first UOA on the truck.

Al- the XD3 has been in for about a month now and will probably be changed at the end of the week when the intake gaskets are changed. Its a real shame to dump the XD3 0-30 so soon!!
Thanks,
Steve

 

[Al]

quote:

---

Originally posted by sm:
Triple Se7en- went with the XD3 just to try something new. Actually oil consumption was nil;no top up added. Have been using syn in the truck for the last 85,000km; but this was my first UOA on the truck.

Al- the XD3 has been in for about a month now and will probably be changed at the end of the week when the intake gaskets are changed. Its a real shame to dump the XD3 0-30 so soon!!
Thanks,

Has the dealer stated that they are going to change them for free??
Steve

---

 

[buster]

Notice on this sample what wearcheck considers abnormal. Fe- 150ppm / Pb - 50ppm.

 

[Mackelroy]

((i think it is the dreaded intake gasket leak.))

I had the 98 chevy truck, and I friend had the same year 454, he went through 2 intake gaskets cause they kept leaking , and when I developed it at 56,000 miles I traded for a toyota. When I bought the truck the salesman told me they loosened the topends on them alittle for better MPG and they burn alittle more oil. I looked at him crossed eye Like okay in not believing. But right off the bat the truck was burning of quart every 3,000 miles.

But out of the last 4 new trucks, chevy,ford, and Toyota,nissan.

the Chevy and Ford were the most troublsome, although the ford was really nice after having it in the shop 3 times in 6 months cause the EGR valve was staying open on start up. I finally fixed myself, oh and the cowl leaked water and the windshild also. On the Chevy Other than the burning oil intake leak and headgasket leak and body grown the chevy, and having to replace some steering components.

Out of the 3 toyotas and 1 nissan they gave me no trouble from defects in material and workmanship.

I've learned my LESSON>G<

 

[Jim 5]

My experience with my '98 chevy k1500 with the vortech 350. 170k miles.

- Intake manifold leak
- fuel pump failure
- (lots of brakes...but this is a wear item)
- 3 inside door levers broke
- 2 outside door levers broke
- water pump failure
- driver's seat broke...dealer couldn't fix it in 3 tries...welding shop repaired it.
- catalytic converter failed
- pitman arm replaced due to unusually high wear
- GM used every possible opportunity to deny my warranty claims.

My dad's '89 toyota pick up. 3.0L V6 170k miles:

- Starter points (I know alot about cars, and I don't know what that is) failed at 160 miles.
- Head gasket failed at 120 K miles...repaired at private garage. 2 years later at 120k miles, got a letter from Toyota: "If you've ever had a head-gasket failure, please send us your invoice for the repair and we'll reimburse you" My dad sent the invoice and received a cheque from toyota inside two weeks.
- no other problems.

Based on reliability and the way each company treats its customers, I know what my next truck will be!