Just Picked Up V6 With Known Bad Head Gasket. Shakes Terribly

jruppert

Founding Member
Oct 20, 2001
294
1
19
45
Michigan
I picked up a 2000 v6 for $500 with a known blown head gasket. I drained coolant and replaced plugs. My plan was to get it into the garage and shut off for repairs. Compression is next to nothing in front 2 passenger side cylinders, cyl 1 and whichever is one behind it. Finally got the engine started. It shakes violently.
So I have a few thoughts running through my mind. One being true worse, I bent rod and the more logical is the fact that those two cylinders have around 25 lbs of compression.

Thoughts?
 
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wmburns

SN Certified Technician
Aug 14, 2009
5,842
505
194
Houston Texas
Any water in the oil?

Any oil in the coolant?

What happens if the spark plugs and fuel injector connector is removed from the affected cylinders (1 & 2)?

But the bottom line is IF you want to know for certain the choices are:
  • run a cylinder leak down test
  • pull the cylinder heads and visually inspect.
  • pull the Whole motor and inspect on the engine stand.
OBTW, pay special attention to IF this V6 is internally balanced or externally balanced. The 2000 model year changed from external to internal balance half way through the model year. DO NOT mix/match parts between internal/external balance.
 

jruppert

Founding Member
Oct 20, 2001
294
1
19
45
Michigan
I've been researching the idea of going with a 4.2. I became aware about the 2000 model year changes. As for the compression test, I found cylinder 1 and the cylinder behind it to have roughly 25 psi. I didn't check the cylinder behind it. I did check the cylinder on the driver side at the very front. That cylinder had roughly 150 psi. I will remove the top end the Saturday and see what I see. I was just afraid of replacing the head gaskets and putting everything back together and finding out I had a bent Rod. The only reason why I'm thinking bent Rod is because water does not compress. I learned that the hard way when I was 17 years old and drove my 87 Mustang through an area that was flooded. I ended up bending a rod and it shook like crazy.
 

jruppert

Founding Member
Oct 20, 2001
294
1
19
45
Michigan
The radiator was empty when I picked up the vehicle. The engine head oil I could not tell if it had any coolant in it. It didn't appear to be milky. It just appeared to be rather thin. I took my chances on the vehicle being only $500.
 
Mar 28, 2017
2
1
13
65
You have a bad head gasket-replace,next your harmonic balancer is bad-replace,very common on late 99-early 00 v6 engines, you cannot tell the balancer is bad just by looking at it,it makes your whole car shake like crazy, low PSI on two cyls. is blown head gasket
 

biker360

Active User
Dec 26, 2017
10
0
1
39
wausau,wi
You have a bad head gasket-replace,next your harmonic balancer is bad-replace,very common on late 99-early 00 v6 engines, you cannot tell the balancer is bad just by looking at it,it makes your whole car shake like crazy, low PSI on two cyls. is blown head gasket
I rebuilt head shaved plus all new gaskets
and car is 96 motor is 97 not 2000 or 99