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Tary substance in 100% synthetic oil change........

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jcy110

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Tarry substance in 100% synthetic oil change........

Hi, I have always used 100% synthetic oil for my oil changes on the 2001 Tahoe. I have 158,275 miles on it and I am the original owner. Lately when I change the oil (every 3000-4000 miles) I see a tarry buildup on the face of the oil filter and small chunks of the same stuff in the drain pan after I empty the used oil into an original container for recycling.

Here are some pictures:

http://www.1pcmedic.com/2001tahoe/oil1.jpg
http://www.1pcmedic.com/2001tahoe/oil2.jpg
http://www.1pcmedic.com/2001tahoe/oil3.jpg

I thought 100% synthetic oil was supposed to stop this kind of thing from starting.

Would an antifreeze leak into the oil cause this problem? There isnt any evidence of foaming or condensation in the filler cap or on the dip stick.

I feel that as some piont this gunk is going to clog something critical maybe even the oil pickup screen.

Anybody have any ideas??????????????????????????///
 
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antifreeze was my thought also but in conventional oil you get a brownish substance usually visible in the oil filler cap. I'm not sure if synthetic reacts differently. Any loss of coolant in the recovery/overflow bottle? If you have radiator cap, have you checked when the engine is completely cold if the fluid level is all the way to the top?
 
Re: Tarry substance in 100% synthetic oil change........

I have slowly been losing antifreeze, but I see drops on the driveway that dont evaporate too quickly so I feel its extenal at this point. When the antifreeze gets on the hot exhaust pipes it gives off a hot crayon smell and that is what I have been getting for a while. Even before this sludge problem sufaced. My mechanic will look at it shortly to see where the antifreeze is seeping from. Ive got 158,275 miles on it. Runs great, rides great. Just have a valve tap on cold startup that I feel is related to the gunk buildup. When the engine warms up it goes away.
 
well if it's something like a head gasket they have a test to check for hyrdocarbons in the cooling system, see if your mechanic can do that.
 
Re: Tarry substance in 100% synthetic oil change........

I have been having to add 1" to the coolant reservoir every 3-4 months. When I change the oil I see a few orange drops on the undercarriage leading me to believe that there is a small external antifreeze leak. Also I get this melted crayon smell which I believe is the antifreeze hitting the crossover pipe when hot giving off the wax smell. I will let you know what my mechanic finds when he takes my car when I am on vacation for a few weeks unless
something surfaces before then.............
 
I'd run a can of Seafoam through the crankcase for about 15 minutes before the next oil change if it were mine. Looks like some kind of gunk for sure, but synthetic shouldn't do that. What brand are you using? I run Mobile One in my Equinox and it doesn't look anything like that between the 7,500 mile oil changes I do.
 
I use the Walmart 100% synthetic in all 3 of my cars and this is the only one with the problem......
 
Chuzz said:
I'd run a can of Seafoam through the crankcase for about 15 minutes before the next oil change if it were mine. Looks like some kind of gunk for sure, but synthetic shouldn't do that. What brand are you using? I run Mobile One in my Equinox and it doesn't look anything like that between the 7,500 mile oil changes I do.
Click to expand...

I looked at the Sea Foam product and it says to add 1 1/2 oz per quart to the crankcase, its a 16oz can/bottle. Do you mean add the whole 16 oz can or follow the directions on the can?????
 
I'd follow the directions on the can, about 1/2 the can for 5 quart engine.
 
Sorry about not getting back to you sooner, man. The wife isn't doing well and between taking care of her and trying to fix that frigging seat belt light, I forgot about your post. I'd use about 8 oz in it and run it for about 15 minutes before changing the oil.
 
Chuzz,

Just picked up a can of Sea Foam at Walmart, 8.99. Im going to try it in the nex few days. Just Idle the car for 15 min or drive it?

Thanks!
 
idle the car do not drive it, then change the oil
 
Post back and let us know if that cleans it up some. But, it does sound to me like you've got a water leak somewhere that's seeping into the oil. I had an 89 Astro van that developed a leak in the intake gasket, but it showed up as a chocolate milk-shake in the radiator. I thought it was a head gasket, but fortunately I'd purchased and extended warranty from the selling dealer and they had to fix it. It was a blown intake gasket instead of head gasket, but they took 3 weeks to fix it and get it back to me. I'm not sure, but perhaps your water pump is leaking on the back side by the impeller and dripping down into your oil pan that way. Of course, I'm not a mechanic and don't claim to be. I have too much respect for the guys that are mechanics.
 
I added the 8 Oz to the oil and idled it (my wife took it to the store before I started)for 15 min. The oil only had 1000 miles on it and just looked amber as I drained it. Filled up again with the walmart synthetic and a new filter. No buildup on the filter and just very small chunks came out of the drain plug.

My son started it in the morning for the last 2 days and said the loud tapping had stopped.

The seafoam treatment at walmart was 8.99, best 8.99 I ever spent. Most of those additives are BS but it seems like this one really worked!!!!!!!!!!!!!!!!

I hope this did it. I will probably do the same in another 2000 miles.

Just a note: on the can it said you can add it to a NEW oil change and run it until the oil gets dirty..........guess you have to keep checking the dip stick every day or few days until its time to dump it.

I might try that after the next oil change and see if I can get it good and clean before the cold winter of the Fall starts to set in. It was definitely worse when it gets cold out.

Many many thanks again!!!!!!!!!!!!!!!!!!!!
 
I've read some great things about Seafoam and have used it a couple of times. I've personally not noticed anything miraculous by using it, but then again, I'm very anal about taking care of my engines and hate to use anything that's not recommended from the manufacturer. The good news is that it seems to have helped your situation. I don't know about adding it to the oil and running it between changes though. It seems to me that it would thin the viscosity somewhat.
 
I think that 8 oz. in 160 Oz of oil isnt really that bad (5%). If the stuff dissolves the sludge slowly then driving it locally for a few days couldnt hurt. Im not saying take it on a cross country trip, just change the oil, add the seafoam and drive it and check the oil color like they say and dump it when it looks dirty.

The Tahoe was started for the last 3 days and my son said the tapping was almost gone.

I will get up early tomorrow and start it myself. I will let you know if I add some and drive it a little and let you know the outcome. Like I said, the colder weather will tell the real story.

Thanks again, John Young
 
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Well, I don't know where you are, John, but it's going to be at least five months before we get any more cold weather here in Tennessee.
 
I'm in NJ. I started the Tahoe myself today and there is still some tapping on the passengers side of the engine. I will add the seafoam and drive it locally and see if that clears things up. I will let you know what happened.
 
Chuzz, went to PA for a few days this past week. It was 47 in the morning............tap, tap,tap.........when I came home I added the other 8oz of seafoam to the oil. I will drive it until the beginning of next week and dump the oil and filter and refill with new synthetic and see if the Tahoe quiets down. I may have my mechanic throw in a new set of lifters when I am on vacation in a few weeks. I will let you know if anything changes.............
 

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