Oil in new motor turned to jelly....why?

RSport · Post by **RSport** » Sat May 23, 2009 11:23 am

I have build ~20 or so of this particular engine and not had issues like this.

Delo 15-40 used during breakin with synergyn assembly lube.

Oil came out gloppy almost gelatin like...I have never seen oil do this in my life.

Any ideas?

beth · Post by **beth** » Sat May 23, 2009 3:35 pm

If there is a very small coolant leak containing antifreeze into the oil this will happen after it has been run for some time.

I am not talking about the "milkshake" or foamy oil you see with a leaking head gasket. The oil will appear like gelatin and will not drain even with the drain plug out if it has been run long enough.

This is usually caused by a very small crack in the head or block that lets antifreeze/coolant leak into an oil passage or crankcase at a very slow rate. If the engine is still together, remove pan and pressurize cooling system. Wait a while and inspect for a few drops of coolant in the crankcase or oil drainback in the heads/valley.

This only is possible if antifreeze/coolant is used, it will not happen with water.

The chemicals in the coolant that don't evaporate combine with the oil to cause this.

RSport · Post by **RSport** » Sat May 23, 2009 9:03 pm

Beth,
Thanks for the reply.

This is a water only coolant system. No anti-freeze is allowed at our local track.

Do the sam thoughts apply?
If I flush engine and replace with fresh new oil and it happens again can I assume this is some sort of water?

beth · Post by **beth** » Sat May 23, 2009 9:57 pm

RSport wrote:Beth,
Thanks for the reply.

This is a water only coolant system. No anti-freeze is allowed at our local track.

Do the sam thoughts apply?
If I flush engine and replace with fresh new oil and it happens again can I assume this is some sort of water?

No, water will not cause this problem unless it's enough to turn the oil white and foamy.

Are you sure the customer didn't add some kind of oil additive? Was the oil temp monitored?

af2 · Post by **af2** » Sat May 23, 2009 10:01 pm

beth wrote:
No, water will not cause this problem unless it's enough to turn the oil white and foamy.

Are you sure the customer didn't add some kind of oil additive? Was the oil temp monitored?

Excellent!!! Advice!!!!

2x4b4fun · Post by **2x4b4fun** » Sun May 24, 2009 12:11 am

Hey, had the same problem when I went to freshen my 540 over the holidays last winter. Been doing this over 30 years and never seen anything like it. When I pulled the drain plug nothing came out! The motor had been sitting for about 2 months after finishing at Steele last year (ran mid 5.60s there) and had given no indication of oil problems during 26 passes made there. I dreaded what the lower end would look like but it was ok. The oil did a good imitation of jelly or almost jello, I had to scoop it out. I can only assume it gelled while sitting so long. Lucky it was out and not able to be started I guess. I was also using a 15w40 but it was Shell. The low sulfur version and the first I had used since using up my supply of the older oil. No additives other than a little assembly lube. There were no more than 50 passes on the oil (one weekend and 4 days at Steele). Runs on gas and no obvious coolant leaks but I was running a light mix of anti-freeze and a corrosion inhibitor. Never thought to pressure test it because I didn't associate the problem with a coolant leak. Can this be a probem with any oil or just the 15w40 low-sulfur diesel variety? I have certainly had my share of major/minor coolant leaks and but never with this result.

RSport · Post by **RSport** » Sun May 24, 2009 12:31 am

its a personal race car. The car sat for a week after racing the last week. Oil temps have always been good....but this last 2-3 weeks oil pressure what pretty high when hot. That concerned me and I was having a bit of a leak out the valve cover gasket.

When I opened up the valve cover I knew things wernt right and realize the jelled oil was slowing oil draining out the head and thus was backing it up causing the oil leak...

unless a crewmember or employee added something I am clueless.

kirkwoodken · Post by **kirkwoodken** » Sun May 24, 2009 1:05 am

I thought this happens from extreme gas dilution of the oil. I may be wrong.

GregGood · Post by **GregGood** » Sun May 24, 2009 11:31 pm

I asked a gentleman that knows a lot about oil about this. Here is his response. I edited out the name of the oils.

Greg,

One thing I know can cause it is additives in the gasoline. We ran extended drain tests using New York City taxis. ****** did poorly, conventional mineral oil ******** did better. It was because the detergent additive in the gasoline was not soluble in the polyalphaolefin and so when the dispersants in ****** were used up, the fuel additive formed a sponge-like structure and created the jelly. ******** did better only because the fuel additive was soluble in the mineral oil itself. It did get very, very viscous, but did not turn to jelly. The ****** cars were fine until the engine was turned off and the oil cooled (like when the driver stopped for lunch.) Whe the engine was restarted, it didn't last long.

The oil was "normal", the fuel additive was "normal" and it was merely due to the hydrocarbon based additive not being soluble in the PAO. An oil using Group III base oil was also OK in the taxis, but we ended up shortening the drain intervals before finding out if Group III and the cheap mineral oil performed differently.

Even so, this is surprising since one of the features of diesel oil is that it has a lot of dispersant. Diesel oils in diesel service have to tolerate 5% or more soot getting in the oil, which will also thicken it. On the surface it would seem an additive from fuel would be handled by the dispersant, but maybe not.

If these engines used methanol, sometimes people or the track adds an upper cylinder lubricant.

If the gel can be made suddenly runny with (a) a little heat or (b) vigorous stirring then that would follow the fuel additive problem we saw.

Hope that helps.

End quote.

Piledriver · Post by **Piledriver** » Mon May 25, 2009 2:26 am

Well, Rotella-T oils are dino (15W40) or group 3 (5W40), so those weren't the oils having issues in the taxi test.... I dangerously assume, but were the oils mentioned earlier in the thread?

Really Curious what the offending fuel additive was.

GregGood · Post by **GregGood** » Mon May 25, 2009 1:26 pm

It was a comparison of a popular synthetic oil against a mineral oil, both used with a popular fuel additive. The synthetic jellied, the mineral oil just got thick.

The hypothesis is that the fuel additive molecules survive combustion and end up in the oil sump where they can react with the oil.

Greezer · Post by **Greezer** » Mon May 25, 2009 1:52 pm

Have a Nice Day

Gunner · Post by **Gunner** » Tue May 26, 2009 6:49 am

GregGood wrote:I asked a gentleman that knows a lot about oil about this. Here is his response. I edited out the name of the oils.

Greg,

One thing I know can cause it is additives in the gasoline. We ran extended drain tests using New York City taxis. ****** did poorly, conventional mineral oil ******** did better. It was because the detergent additive in the gasoline was not soluble in the polyalphaolefin and so when the dispersants in ****** were used up, the fuel additive formed a sponge-like structure and created the jelly. ******** did better only because the fuel additive was soluble in the mineral oil itself. It did get very, very viscous, but did not turn to jelly. The ****** cars were fine until the engine was turned off and the oil cooled (like when the driver stopped for lunch.) Whe the engine was restarted, it didn't last long.

The oil was "normal", the fuel additive was "normal" and it was merely due to the hydrocarbon based additive not being soluble in the PAO. An oil using Group III base oil was also OK in the taxis, but we ended up shortening the drain intervals before finding out if Group III and the cheap mineral oil performed differently.

Even so, this is surprising since one of the features of diesel oil is that it has a lot of dispersant. Diesel oils in diesel service have to tolerate 5% or more soot getting in the oil, which will also thicken it. On the surface it would seem an additive from fuel would be handled by the dispersant, but maybe not.

If these engines used methanol, sometimes people or the track adds an upper cylinder lubricant.

If the gel can be made suddenly runny with (a) a little heat or (b) vigorous stirring then that would follow the fuel additive problem we saw.

Hope that helps.

End quote.

The oil that did poorly has 6 * that could be Mobil 1 if that is it your info is old.
Mobil 1 no longer contains PAO

About a year ago members on BITOG took up a collection and got enough money to hire a Lab to analyze Mobil 1 it is no longer a PAO based oil it is group III

srv601 · Post by **srv601** » Tue May 26, 2009 4:19 pm

i had something close to this on a bbc in a marine engine on a new rebuild turned out machine shop had put new exhaust guides in my 990 heads and pushed them out the wrong way and damaged the heads they leaked water thru the exhaust guide and then thru valve springs it was a pain the a@@ to find this leak. heads where cracked and had to be put down. engine had a inch of white foam or paste in valvecovers and oil was like glue.

hope this helps.roger

GregGood · Post by **GregGood** » Tue May 26, 2009 7:04 pm

Gunner wrote:
The oil that did poorly has 6 * that could be Mobil 1 if that is it your info is old.
Mobil 1 no longer contains PAO

About a year ago members on BITOG took up a collection and got enough money to hire a Lab to analyze Mobil 1 it is no longer a PAO based oil it is group III

The post wasn't about any particular brand that may or may not contain PAO anymore. It was about the effects of fuel additives on PAO and mineral oil.

I believe there are PAO oils still on the market.