Blown head gasket?


Asked by Feb 21, 2016 at 02:33 AM about the 2000 Chevrolet Silverado 1500 Ext Cab Long Bed 4WD

Question type: Maintenance & Repair

Well, I bought this truck a few months ago.  It's a
2000 chevy silverado 1500 with the 5.3L.  I went to
change the oil yesterday and while i didnt see any
coolant in my oil, when i took my oil refill cap off, it
had moisture puddled up on the underside of it and
was gunked up with a chocolate milk/rusty color.
You could literally see moisture in the refill neck
and on the cap and both were caked with that
colored gunk.  

I've also noticed some little things with it.  Ive lost
a little bit of coolant (about an inch out of the res.
and have lost about a half quart to a quart of oil
since i bought it (driven 2000 miles since).  
Sometimes it won't start when I first turn the key
and it rolls over a few times, I have to turn the key
back then turn it over again before it will
start(possible compression problem).  Also, my oil
pressure gauge gets bouncy when idling and it
doesn't quite idle right, you'll feel a little rumble
every 5 seconds or so.  

Besides all that the engine runs fine and idles
decently except for the very slight rumble every 5
seconds.  All signs point to a blown head gasket
do they not? I'm also worried about further damage
to the engine because I have a feeling it was like
this before I bought it and I've been driving it this
way and who knows how long it's been driven like
that before hand.  If it is a blown head gasket what
kind of repairs will most likely have to be done to it
besides new head gaskets as far as machining,
cleaning, replacing, etc.

I know it's one of the more  difficult repairs to
make but I am consider doing it myself with some
help. I'm mechanically inclined I just never tackled
anything this substantial and am not sure what
else will need to be done to the heads or anything
else besides the gaskets.  Or what special tools I'll
need. Any advice or thoughts will be appreciated. I
am having my go to mechanic look at it soon I'm
just freaking out here and want to get some
second opinions.

4 Answers


Ok, first off under your oil cap what you see is normal. Its just condensation collecting because of the cold & hot. Your oil usage sounds normal also. If your motor is not overheating, and you don't see any oil in the coolant system, or coolant in the oil, plus no white smoke coming out the exhaust, I don't think it is a blown head gasket. You can do a couple of test to check, 1 by pressurizing the coolant system to see if it holds pressure, 2 by doing a compression test on the cylinders. 1 or 2 cylinders would show. low in compression. The starting thing may be plugs and wires, but I would check the fuel pressure. It should be at 56 to 63 lbs.


I have been working on my own vehicles and changing my own oil since I was a teenager and I've never seen this before. The amount of that gunk on the cap and refill neck was shocking. It covered the rag I used to wipe it off (which I regret now that I'm going to have it looked at). Your probably right that it's not completely blown but something's not right. The bouncy oil pressure gauge can indicate something wrong with the head gasket as well. Also, the little coolant I'm using isn't pudding anywhere so where is it going? My brother who was a marine mechanic on amphibious veh. and has worked on the 5.3s before was the one who pulled the cap off and noticed it in the first place and said I might have some big problems on my hands. Add in the slight rumble while idling and to me there's just no way this is normal.


Also another cause of the moister could be the PCV and breather system. The PCV system takes crankcase gases created by churning oil and cylinder blow-by and directs them into the engine where they are burned along with the air/fuel mixture. This keeps harmful emissions from entering the air we breathe and prevents the buildup of crankcase pressure. The PCV valve regulates the flow of these vapors. A clogged valve can cause pressure buildup, which can in turn cause gasket failure and oil leaks, and also cause sludge buildup, which occurs when moisture remains in the crankcase and contaminates the oil.

Andrew Olsen

I've seen many of these with residue under the cap and sometimes in the tube. Chances are your the first one to clean the fill tube. 1 inch in the overflow isn't hardly anything and 1 quart after 2000 miles isn't bad. How many miles on this truck? If your not getting white smoke out the tail pipe and the oil drained isn't chocolate milkshake then your head gaskets are fine. The starting thing in the morning sounds like the fuel pressure bleeds off overnight. Either check valve in the pump or pressure regulator. I think your getting alittle ahead of yourself.

Your Answer

Add photo

Related Questions

Silverado 1500

Looking for a Used Silverado 1500 in your area?

CarGurus has 144,777 nationwide Silverado 1500 listings starting at $1,995.


Search Chevrolet Silverado 1500 Questions

Chevrolet Silverado 1500 Experts

#1 John Carson
John Carson
Reputation 1,590
#2 Silverado_owner_2006
Reputation 1,390
#3 Andrew Olsen
Andrew Olsen
Reputation 1,310
View All

Related Models For Sale

Used GMC Sierra 1500"
1,028 Great Deals out of 56,923 listings starting at $2,300
Used Ford F-150"
3,272 Great Deals out of 216,647 listings starting at $1,500
Used Dodge Ram 1500"
522 Great Deals out of 13,738 listings starting at $995
Used Chevrolet Silverado 2500HD"
402 Great Deals out of 33,527 listings starting at $2,499
Used Toyota Tundra"
618 Great Deals out of 26,773 listings starting at $2,500
Used Toyota Tacoma"
625 Great Deals out of 30,504 listings starting at $2,850
Used Chevrolet Tahoe"
1,076 Great Deals out of 36,074 listings starting at $1,700
Used Chevrolet Camaro"
798 Great Deals out of 38,851 listings starting at $2,650
Used Chevrolet Silverado 1500HD"
15 Great Deals out of 306 listings starting at $4,850
Used Chevrolet Silverado 2500"
3 Great Deals out of 271 listings starting at $3,499
Used Ford F-250 Super Duty"
443 Great Deals out of 42,987 listings starting at $2,250
Used Chevrolet C/K 1500"
1,138 listings starting at $2,400

Used Cars For Sale

2017 Chevrolet Silverado 1500 For Sale
8 Great Deals out of 55,355 listings starting at $22,113
2016 Chevrolet Silverado 1500 For Sale
306 Great Deals out of 35,001 listings starting at $17,443
2015 Chevrolet Silverado 1500 For Sale
281 Great Deals out of 8,170 listings starting at $14,948
2014 Chevrolet Silverado 1500 For Sale
434 Great Deals out of 11,056 listings starting at $10,990
2013 Chevrolet Silverado 1500 For Sale
262 Great Deals out of 6,835 listings starting at $7,400