1998 XJ8 VDP with 60K purchased in June '04 with 42K miles. Have flooded it on start 2 times. First time mechanic addressed issue, then about a year ago I let it sit for 2 weeks and put a battery charger on and cranked it a little till it started. Spring of this year the dealer told me I should replace the sensor on the crankshaft, about $800. A friend referred a mechanic who said he could do it for about $400 and I waited. Also, on 2 occasions, once more than 1 year ago the lower radiator hose disengaged and then 2 months ago the upper hose disengaged. I did not think there was damage, but starting was getting more touchy. Took it to referral mechanic who told me that his computer said I needed new fuel pump and a new alternator, almost $1,000. Next day he said he feels the head gaskets are blown and gases are adding pressure to radiator lines. Another $3,000. Now I don't know what to do. Costs seem less than other notes on the forum, but worried he will get it apart and tell me need much more money to put it back together.

Also noterd a couple of comments that doubted head gasket problems on the XJ8. Sorry for long history, but any advice would be welcome.

Lee

 

A simple cooling system pressure leakdown test and/or 8 individual cylinder leakdown tests should tell you (or your mechanic) whether the head gasket is leaking.

One can also sometimes get some intel from looking at the spark plugs - which must be pulled for the leakdown tests anyway... If one is unusually different looking than the rest (ranging from rusty to abnormally clean) you get a hint that something strange is going on in that cylinder.

Lastly, if your battery is holding charge, then alternator is not a likely problem - but are a common scapegoat from less than knowledgable mechanics. Fuel pump pressure and flow can also be tested independently - his computer (or is it his own experience?) seems to be coming up with somewhat ambiguous answers.