Ad0911

I have a 4.5L engine with compressionloss on 1 cilinder due to leaking headgasket. Ist it a viable option to have just 1 cilnder rebuild?

Jim bailey - 928 International

No ...

Imo000

Just change the headgasket/s and the compresson sould be back to normal.

Ad0911

As noted, the compressionleak is towards the carter ventilation, so I suppose it is leaking alongside the cilinderwall and piston. I don't think a new headgasket will solve this problem.

Jim bailey - 928 International

What you are looking at is a top end rebuild. The timing belt must be removed then BOTH cylinder heads. Once the heads are removed you can examine the corrosion on the head surface and corrosion/ erosion on the top of the cylinders . You are looking for WHY the gasket failed. Usually the heads will need to be machined resurfaced and while in there it makes sense to put in new valve guides and seals touch up the valve seats/valves. All the intake will be off so gaskets seals hoses need changing..... Doing this much work with the engine in the car is far more difficult than removing the engine and working on a stand where it is so much easy to work on. But removing the engine seems like such a big step that it is hard to do because with the engine out it feels like you no longer have a car ! And the while you are in there opportunities also increase

mark kibort

I have a brand new rebuilt 4.7 short block ready to go. while you have the engine out, you could just swap this new one in. It has barely been broken in, and it is perfect. (new rings, bearings, etc) it would even raise the compression a little. $1500 and its yours! easy way to gain about 30-40 hp
mk