1997 Pontiac Grand Prix Mobil 1 5w-30 3,086 miles

[wizzells]

Just got the UOA results back for my '97 Grand Prix with 3.8L V-6. I had a recent upper intake manifold coolant leak and was worried that it might have gotten into the oil. I sampled the oil about 400 miles after the intake manifold leak was fixed. The results really arent too terribly bad, but there is a possibility that some coolant was getting into the oil. I would like to see the lead number come down some, but Im at least content at this point that its doing ok. I have been running 6000-7500 mile OCIs with Mobil 1 for the past 45,000 miles. 117,400 miles on the car, 3086 miles on the oil which was Mobil 1 5w-30.

• Aluminum 3
  Chromium 1
  Iron 15
  Copper 9
  Lead 9
  Tin 1
  Moly 63
  Nickel 1
  Manganese 0
  Silver 0
  Titanium 0
  Potasium 27
  Boron 112
  Silicon 11
  Sodium 5
  Calcium 2401
  Magnesium 18
  Phos 762
  Zinc 933
  Barium 0

Comments and insight are always welcome. This is my first UOA, but I havent really seen a reason to do one before this. I plan on doing another sample in about 1500 miles on the Chevron Supreme I have in right now to see how things are going. Does anyone know if the possibility exists on this engine for coolant to enter the engine during this repair? or am I looking at problems in the near future with another gasket. Thanks all

 

[wizzells]

Forgot to add some other stuff...

vis @ 210: 59.0
flashpoint: 390
Fuel: insol.: 0.4

No make-up oil was added

 

[TooSlick]

Some of this bearing wear is from previous coolant contamination, as is the trace of potassium. Some of the silicion, ie silicate, could also be from antifreeze. The lead and coolant residues should dissipate with the next oil change, provided the leak has been fixed.

Coolant contamination results in the formation of organic acids and these cause corrosive wear of softer bearing overlay materials. Most of your coolant would have been burned and not gotten into the crankcase, however.

You might want to look at a few of your plugs - burning EG coolant usually leaves a whitish deposit on the electrodes in the affected cylinders.

 

[T-Keith]

Look similar to mine except the lead. Mine was for more miles and only using Chevron dino though. Is the oil change immediately after the repair?

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002334

-T

 

[wizzells]

The oil change was about 10 days and 400 miles after the repair. I had the work done by my mechanic and then changed the oil myself as soon as possible. I would've changed it right after, but time did not permit. Im running an auto-rx cleaning phase right now, so I'll sample at the end of the cleaning phase again to make sure the fix was done right and there isnt more coolant getting into the oil. I wish the mechanic would've advised me to change the oil at the time of the repair because the thought crossed my mind, but he assured me "coolant isnt getting in the oil". Wish I would've known better beforehand.

 

[T-Keith]

If this is the oil that was in during the repair I wouldn't worry at all. Try another UOA at your next oil change to make sure everything clears up. Can I ask where exactly the problem was?

-T

 

[wizzells]

The upper intake manifold gasket failed on the air intake side. I noticed the problem when I smelled coolant when I would first turn on the heater. It was puddling up on the lower intake and the fumes were being sucked in. Luckily I caught it early enough that it didnt destroy the manifold itself. Just needed a gasket replacement...at least thats what Im hoping!

 

[jason07-1zzfe]

Yes it is VERY easy for coolant to enter engine during this repair. If I read it correct you had this oil in prior to, during and for 400mi after repair?
You are braver than I. But looks ok. Hard to tell if it is fixed, there will definitely be coolant still present from pre-repair. (and there is)