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yellow gunk on tip of dipstick

weddow

Full Member
Joined
Jan 8, 2007
Messages
56
Location
Cibolo, Texas
I have been semi diagnosed with a rear main seal leak. I randomly checked my oil the other day to make sure it was still full and at the tip of the dipstick was a yellow gunk. No more than 2mm worth. I wiped it off and checked again and there it was. Did maybe 4 times and then it stopped. It had a Dijon mustard type color and viscosity. My dad said it may be water. Other things I have read is extreme temp changes can cause this. And in Texas we have had a crazy Winter. Anyone else experience this and should I be concerned? Thanks.
 
I'm not an expert, but I will tell you what I've learned from experience.  I had this happen to me on a vehicle years ago.  The oil fill cap also had this same stuff on the underside of it.  I was told a thin layer of it is caused by condensation.  But if it's a thick layer you have water in your oil.  Long story short we ended up having to replace the valve cover gasket, and in doing so we found we had a thick layer of said gunk inside the valve cover.  We ended up replacing the head gasket as it was shot.  Problem solved.  Hopefully in your case it's just condensation.  Good luck!
 
Check front of passenger side head. If you have the 706 heads it could be a cracked head.
These are prone to cracking. Only way to know for sure is to pull valve covers and check.

I did this and I had coolant inside the heads on both sides. Not sure that a blown head gasket creates this but certainly a cracked head can.

There were two types of heads made and I believe the good ones say 862 on them.

Very common with the 5.3. I will be ordering new heads shortly ($300 for pair and I have to send back my old ones)

If you drive the truck much longer before finding the source you are likely going to do extensive damage to your engine.

Rodney
 
yellow foamy jelly like stuff in oil is caused by water or coolant in oil.

Have it checked out.
 
I should have said that stuff is a combo of oil and coolant.

See this thread for what I found in mine...
http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,150622.50.html

Page 3 has pictures of what I found in mine...

If tip of dip stick has yellow on it then the majority of your oil has the same.

My truck hasn't been driven since I saw the yellow on my dipstick. I caught mine well in time since I had no such indications on my dip stick when I changed the oil less than 1,000 miles prior.

I am buying all of my components other than the heads from rockauto in the next week or so. And will also be purchasing the heads during the same time. I hope the weather sticks out so I can replace the heads over a weekend.

I will also post the name of the company I am buying the heads from if I didn't already.

Rodney
 
Thank you everyone for the info and replies. I am mechanically challenged. I just had the water pump replaced about 2 months ago because the dealership said the weep hole was leaking. I had the water pump replaced by a guy I know. (not at a shop). Is there anyway this problem is related to replacing the pump incorrectly? Thx
 
weddow said:
Thank you everyone for the info and replies. I am mechanically challenged. I just had the water pump replaced about 2 months ago because the dealership said the weep hole was leaking. I had the water pump replaced by a guy I know. (not at a shop). Is there anyway this problem is related to replacing the pump incorrectly? Thx

Could be if water somehow got into engine... but by just changing water pump it should not have....
 
The last time I had yellow gunk on my dipstick it was something quite different  :D
It was back in '68, Nam, and I was on a two day leave in Hanoi City, met a couple of local hotties who loved me long time. Turns out that love lasted much longer than expected...peed fire for two weeks.
But I digress, it sounds like coolant in the oil.
 
weddow said:
Thank you everyone for the info and replies. I am mechanically challenged. I just had the water pump replaced about 2 months ago because the dealership said the weep hole was leaking. I had the water pump replaced by a guy I know. (not at a shop). Is there anyway this problem is related to replacing the pump incorrectly? Thx

No way... If you have coolant in your oil it is generally from either a blown head gasket or a cracked head. As I mentioned if you are "lucky" like me and have the 706 heads it is very likely.

If you are mechanically challenged you might find it cheapest to find a low mileage 5.3 engine and have it swapped for yours. Anything else will end up costing you far more money in labor than it would be worth. Or you find a buddy that will do the work cheaply and they cut corners or not sure what they are doing and you end up with a broken truck again shortly.. ( I did this when I blew a head gasket on a cavalier. I didn't have the tools to do it myself and paid someone else $500 to do it... Car lasted about 6 months before it blew the head gasket again... )
 
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