LQ4 inside of heads different coloring
Thread Starter
Teching In
Joined: Jun 2008
Posts: 14
Likes: 0
From: Champlain, NY
LQ4 inside of heads different coloring Have a 2002 LQ4 engine with 88K miles, it is from a fleet maintained vehicle. Bought the truck for it's drive-line for a street rod project. It always seemed to have excessive moisture coming out of the exhaust "only" after warming up...never when cold or first start..but ran always good.
I assumed it had water in the tank and dropped in a couple bottles of water separator which made it worse as I started getting "lean" codes and the engine began to run rough. It was a cab/chassis and the fuel tanks were exposed to the elements after the utility box was removed by the previous owner prior to sale.
Today I did a low pressure leak down test on each cylinder and all eight were excellent to say the least. Just like a water contamination symptom all eight plugs were moist & black (none were water bleached or white), with a water jacket crack, head gasket leak etc,..from my experience the affected cylinder(s) spark plug would be water bleached and the rest normal brown in color.
Going to pull the heads at some point to inspect the innards and heads, then replace all seals. Still feel that water in the tank was the problem.
The inside of the engine is spotless as a well maintained engine would be - but I noticed the valve train on the drivers side head was darker in color than the passenger side head (pics attached)- anyone experience this condition before?
I assumed it had water in the tank and dropped in a couple bottles of water separator which made it worse as I started getting "lean" codes and the engine began to run rough. It was a cab/chassis and the fuel tanks were exposed to the elements after the utility box was removed by the previous owner prior to sale.
Today I did a low pressure leak down test on each cylinder and all eight were excellent to say the least. Just like a water contamination symptom all eight plugs were moist & black (none were water bleached or white), with a water jacket crack, head gasket leak etc,..from my experience the affected cylinder(s) spark plug would be water bleached and the rest normal brown in color.
Going to pull the heads at some point to inspect the innards and heads, then replace all seals. Still feel that water in the tank was the problem.
The inside of the engine is spotless as a well maintained engine would be - but I noticed the valve train on the drivers side head was darker in color than the passenger side head (pics attached)- anyone experience this condition before?
TECH Resident
Joined: Apr 2014
Posts: 985
Likes: 12
Thats funny the last lq4 I opened up was the same way, I just thought it could have been
a replacement head or cleaned up because of head gasket failure, didn't give it much thought after that. I did not find anything wrong with it, I cleaned it up with new bearings and the
usual rebuild, it's running great no problems at all. Good luck
a replacement head or cleaned up because of head gasket failure, didn't give it much thought after that. I did not find anything wrong with it, I cleaned it up with new bearings and the
usual rebuild, it's running great no problems at all. Good luck
On The Tree
Joined: Jun 2012
Posts: 122
Likes: 2
Yep yours look great compared to these see time count 2:00
I also had a set of heads that looked almost exactly like yours only difference was my rockers and springs on bank 1/drivers side had been turned/stained black.. ill have that video up sometime soon, as im going to be posting it asking about why they got stained black, but the other side/bank 2 was normal..
But yeah thought id post this up to show ya just how clean and pretty yours are compared to these.
Really more a less you asked the question i had been wanting to ask about this, i never knew that about the PVC system on bank 1 being the dirty side, btw mine that looked almost exactly like yours was on a engine that had a blown head gasket on bank 1 and the oil was contaminated too..
So how is the bank 1 the " dirty side" what does that really mean ?
But yeah thought id shear
peace
I also had a set of heads that looked almost exactly like yours only difference was my rockers and springs on bank 1/drivers side had been turned/stained black.. ill have that video up sometime soon, as im going to be posting it asking about why they got stained black, but the other side/bank 2 was normal..
But yeah thought id post this up to show ya just how clean and pretty yours are compared to these.
Really more a less you asked the question i had been wanting to ask about this, i never knew that about the PVC system on bank 1 being the dirty side, btw mine that looked almost exactly like yours was on a engine that had a blown head gasket on bank 1 and the oil was contaminated too..
So how is the bank 1 the " dirty side" what does that really mean ?
But yeah thought id shear
peace Last edited by the404man; Apr 21, 2016 at 05:32 AM.
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