Hello "WISE ONES",

It's been awhile since I posted any questions and figured I would offer some entertainment for you. First, Here's my problem or symptom: Within 150 miles of break in time of a complete rebuild my 02 4.0 began having a popping sound as if a can is expanding from heat and released as if you opened the lid. It initially ran great but know seems to hesitate abit when it does this. I'm nearly 99% sure the valley pan gasket is expanding and contracting. It gets worse if I pull a PVC line off and subsides when I put it back. So apparently I have crankcase pressure. My fear is that a brand new head gasket has blown.

As far as codes: It has thrown P0300,P0304,= misfire
P1412= SAI ? It runs and makes noise.
P0130,P134= o2 sensors.
P1171= lean bank 1
No cel light only service soon light

So a little back ground: I bought my 02 disco 2 with 94k from nearly a one owner with service history after 7k from local dealer. At 95k I discovered the common head gasket leaks in the back. So after pulling the heads, I figured I would keep this D2 for the long haul. So I yanked the engine and drive train all out. I have rebuilt everything including trans and TC. I have quite abit of experience of restoration of old school rides so this did not scare me. I took my time and did the research. Below is a list of rebuild high lights:

All new standard bearings: cam, crank all mic to specs, polished only
Top hat liners installed at std bore.
Retained cam and only replaced lifters
New oil pump
Valve job (decked)
ARP head bolts.
AB composite head gaskets
New NGK 7.5 wires and NGK plugs
Crank sensor
***Spent a lot $$$$ and time to do this right.

After all of this, I installed it and was proud of an immediate start up of a quite motor and " No Leaks"

I'm no master technician but have extensive background in wrenching. Performed the cigar test and found no leaks after tightening the throttle body clamp. I haven't pulled the plugs for a compression test yet, hoping somebody would give me some good news that they had the same problem at some point. May be one of these ancillary engine vacuum systems. ?

I welcome you input as well as comedy.

Thanks

 

The service engine light IS the CEL. One and the same.

 

My mistake, I had thought they where to separate ones.

 

Did you mic the cam before you decided to retain it?

Cam wear is common in trucks that had thin oil or longer oil change intervals or oils that do not contain high levels of ZDDP.

I only ask because I had a popping can sound when my cam was worn probably due to the wrong oil being used.

 

The previous owner probably drove it with a bad head gasket which was emitting hot exhaust gas out the side of the head.

You put on new head gaskets but the deck was not checked for true and there was a slight imperfection which allowed the new head gasket to breach and fail.

or you put on made in China head gasket - not Victor Reinz.

More details are needed.

 

Thanks for your response Dave. Can you tell me more about your symptoms?

My machinist mic'd the cam and deck the heads as described above with the valve job. I used comp cams break in oil for 100 miles and drained. No obvious metal in oil. So I thought I would go the rotella full synthetic route and drove it about 20 miles and noticed a slightly noisier top end. Still very quite though. I checked my mech oil gauge at temp and I was only getting about 4-5 psi. So out came the synthetic and placed rottella 15w/40. In which oil psi came back to 10-15 at temp and idle 0ver 50 psi at 1800 rpm. What concerned me was when I drained the synthetic I saw what I will call fine sparkles ( technical term) in the oil. So, I am afraid the cam is toast. I just don't understand the " popping can noise from the valley pan area. It also seems to run we'll unlike a domestic v8 runs with a bad cam.

 

The break in oil in my case (before I knew better myself) was Castrol 5w30 syn. And I ran about 40k with that oil until the cam died. (this is when I found this forum and stopping going to dealers.)

At the time I was still under warrantee and letting the dealer do the service. They switched to the thinner oil by then, which was around 2007 in my case, after they went to servicing mostly RR Sports and LR3's. (overhead hydraulic camshaft)

My symptoms of a warn cam shaft were low throttle response, missing on two cylinders, and the popping sound, which was in fact backfiring intake valves being heard through the air intake, so it was somewhat muffled and hard to tell where it was coming from. It was a popping under load, usually accompanied by a blinking SES light.

The engine idled smoothly and ran under 25 mph fine unless you were in a hurry or on a hill. That being said it was in no way something you would WANT to drive.

The symptoms came on gradually until one day going up a hill noticing weak power I put my foot in it and then it started the popping.

I only mentioned this because I've always heard if you replace the cam or the lifters, always do both.

Not sure if this matches your situation but good luck and keep us posted!

 

New lifters on an old cam will give you lots of sparkles in the oil. Camshafts in these engines wear out pretty quickly, and the lobe shape will be unique to each lifter base. New lifters will have limited contact area on an old camshaft so there will be higher stresses on the areas that are touching which will lead to rapid wear of both the camshaft and lifter base.


You can pull the valve covers and check the movement of the rockers to confirm if it's a cam issue.

 

Well, I didn't follow my gut instinct and looks like I'm paying for it. I have always replaced both in prior builds, but I figured you hear folks just replacing lifters from time to time in these motors. Last night I performed compression check on pass side and all was good. So, I'll tear it back down in a few days. Thanks for your insight and confirming my ignorance. Any comments on cam and lifter combos?

Again, I appreciate your input.

 

I know it's been awhile but I figure late is better than never. So the diagnoses was blow-by. I inadvertently installed the #8 piston/rod 180deg out. Thus causing the to cap oil squirter to squirt elsewhere. It ruined the sleeve and rings only. My big bad and probably got distracted. Soo.. The tin can popping sound was literally the tin valley pan popping up and down.