Hello,

I have problems with my SV8 engine, in cold conditions after engine starts it loosing power and I have misfires. When engine become warm it works fine (so far) but it consuming more oil then normal (1l per 2000km)
Jaguar dealer did a compression test which results are not good.

I have quite low compression generally, around 8, 1, 3 and 7th valve even less. Regarding dealer its too low and +-12 is expected in room temperature. They saying I need engine rebuild, probably replace piston rings etc...
I am looking for piston rings part on the internet but I cant find anything.
Any advice where to buy piston rings for SV8?

 

You need to find out more - low compression can be due to burned or badly seated valve. If it is valve issue, you can solve it by removing head and lapping valves. It also makes sense to replace valve stem seals at the same time.

Burning oil can be due to a bad oil scraper ring, but it also could be due to a shot valve stem seal.

Jaguar dealer doesn't have expertise with rebuilding engines. You need to take it to a shop that specializes in this type of work.

Before you do that, try flushing (strong detergent into oil) and steaming (water mist into intake) engine. In case this is carbon buildup or sludge that caused this issue. It is long shot, but is much cheaper than the alternative.

 

To replace piston rings you need to have pistons disconnected from the crankshaft and out of the block. This requires taking engine out of the car, heads removed, and oil pan removed to access crankshaft. At that point it is cheaper to just swap engines, as this is at least a week of labor.

 

Try this,,

Use two cans of BG EPR (I think part number is 109) Run the engine when it is warm before adding the BG EPR and keep the revs held at 1200-1400 rpms for 20 minutes and then do an oil change. EPR restores compression and should help with oil rings falling back in their place.

Personally I have tested this product with AMAZING results!!! Oil consumption was down to almost none and compression restored. Youtube this product and see the results for your self. Really it is worth it before you go and do a full engine swap, I mean what's it gonna hurt? new engine? you're doing that anyways.

Best Of luck

 

any updates?

 

The OP doesn't indicate the year of the vehicle, nor the number of kilometres/miles.

Before condemning the engine, someone should remove the inlet manifold and see if there is carbonising of the valves causing them to not close fully. That could account for the low compression and oil consumption.

 

Agreed. Engine rebuilds are really the last resort especially for low compression. Makes complete sense to check everything that's cheap to fix first.

"SV8" implies 4.2 to me as I thought it was a pretty old model derivative but not guaranteed.