4.7 engine woes

firebirdtony · Oct 2, 2016

My 4.7 has been running hot since it was stolen.
Theres no Water in oil. No misfire. Smokes only at start up Then smokes gone. Med knock up top until engines warm then it goes quiet. Compression was 95 on 6cyl and 110 on 2. Plugs looked the same except 1 which was black. Dry not coated in oil. Any advice on whether i should rebuild? Or just scrap the truck? I cant afford 2500 for a reman also cant find one with low miles from a salvage yard. Everything s 190k miles and they want 1800 or better for that.

Its my first dodge and truck any advice would be helpful.

firebirdtony · Oct 2, 2016

These are the plugs 6 months old

firebirdtony · Oct 2, 2016

Pass side plugs

JAMMAN · Oct 3, 2016

The darker one wouldn't happen to be from #6 would it?

icywhite · Oct 10, 2016

If you can swing a wrench do it just have the heads checked to make sure their not warped and might as well do timing chains while in there I've done it twice in the 11 yrs I've had the truck

firebirdtony · Oct 10, 2016

Darker one came from no3

JAMMAN · Oct 11, 2016

The compression loss and overheating/white smoke are probably unrelated.

Head gaskets being blown does not necessarily mean you will get oil in the water or water in the oil. Most often on a 4.7 it is between a cylinder and a cylinder or between a cylinder and a water jacket hole. Your pressure cap on the reservoir will release any excessive radiator pressure but when you shut it down for the night the water (still pressurized naturally) seeps into the cylinder(s) and will cause the smoke/dripping out the tail pipe AND possibly a bad miss for a few seconds. The plugs that are whitest probably are atop the cylinders with leaks.

During normal engine running the truck might not even miss from the gasket as the leak is slow.

Your head gasket is certainly blown but I bet it is a valve or valve lash adjuster or rocker that is causing the lack of compression.

Yes team I know it "could" be rings but highly unlikely.

Any way it goes you must pull the heads and have them surfaced

firebirdtony · Oct 12, 2016

JAMMAN said:
The compression loss and overheating/white smoke are probably unrelated.

Head gaskets being blown does not necessarily mean you will get oil in the water or water in the oil. Most often on a 4.7 it is between a cylinder and a cylinder or between a cylinder and a water jacket hole. Your pressure cap on the reservoir will release any excessive radiator pressure but when you shut it down for the night the water (still pressurized naturally) seeps into the cylinder(s) and will cause the smoke/dripping out the tail pipe AND possibly a bad miss for a few seconds. The plugs that are whitest probably are atop the cylinders with leaks.

During normal engine running the truck might not even miss from the gasket as the leak is slow.

Your head gasket is certainly blown but I bet it is a valve or valve lash adjuster or rocker that is causing the lack of compression.

Yes team I know it "could" be rings but highly unlikely.

Any way it goes you must pull the heads and have them surfaced

Thanx man

I guess I'm going to pull the engine and just rebuild it. Right now I have very high miles but good oil pressure and no bearing issues. Since I have no spin bearings. It might save money on block work if I don't need new rods or a crankshaft or possibly dont need the block bored. I can usa the money and just buy new heads and bearings if everything measured out ok

4.7 engine woes

firebirdtony

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