Hi all,

So my head gasket went out and I went ahead and tackle the job. I have everything out now and is about to send out the heads to get it resurfaced. However, as I called the machine shop, the machinist stated that you're not suppose to resurface or touch the heads on these cars; although, he would do it, but just under a no warranty waiver due to what Jaguar states. Is that true and what am I to do here? Thanks much in advance.

 

Just have him deck check them for true and clean them up....Jag builds their clearances tight.

 

Wow! I'd find a Jag specialist, find out which machinist they use and deal with them...that's crazy!

 

They are only supposed to be done as necessary, but here's a contact you may want to call. They state no question goes unanswered...Contact Black Dog Manufacturing

 

Thanks very much guys for the quick response I really appreciate it

 

The heads can be milled. I'm not sure how much though. If the heads need like .010 taken off, make sure you send the timing cover with the heads so they can mill the same amount off the top where the front of the valve cover gaskets meet the cover. They'll know what do if they're reputable. I'd have them perform a complete valve job on the heads, replace valve stem oil seals and have them perform the valve adjustment.

 

will do thanks

 

Plus, it changes the distance between the timing chain sprockets yet of course the length of the chain remains the same. You could wind up with the valves 1-3 degrees out. Have not done one of these engines, but on some Toyota engines, there's a set of alignment dowels on the cam gear sprockets which allow adjustment to compensate. Not sure how the Jaguar cam sprocket alignment gets adjusted if at all. You may also be able to compensate with a thicker metal head gasket. But I'd look into that before doing machine work.

 

I just had a head on my 2000 xk8 surfaced. They took .007 off of it. I didn't have the timing cover done. I put just a dab of sealant at the head timing cover joint while putting on cam cover. I have had no problems.

As for the timing of the engine you have no problems there as long as you time it as shown in the manual. The sprockets on our cam are adjustable so as long as the cams and crank are locked down and the chain is tight it should time perfectly.

 

Thanks much for your reponses. I'm curious. I have the heads sitting here and the machinist mentioned if he had to disassemble the head, I'm assuming he's talking about removing the valves, etc; as I'm sure they'd need to come off for the job. That it'll be additional charges; pretty much doubling the price altogether from what I was quoted. However, how the car sounds when idling/driving, it is very quiet. No rattling or ticking of any sort. From that I assume the valves are fine. Now with that said, can I pull out the valves and put them back myself without throwing anything off? And if so, what tools are required and are there any DIY's on here that will guide me in the process? What would be your recommendations; take on a DIY task here or better to just send it in as is and call it a day and pay double the cost. Of possible, I'd rather use that extra $$$ for a new fuel pump if not necessary for the guy to do that addition; as my secondary pump is currently out. Thanks again.

 

Ok let's start from the begining. You removed the heads because of bad headgaskets. Why did you take the heads in to be resurfaced. Are they warped and if so how much. Or did you just sent them in as a preventative measure. If you didn't check the heads for warpage ask the machinist how much they are out.

If the heads are not warped they do not need to be resurfaced. Since you have the heads off I would put in new valve stem seals but you will need a valve spring compressor to do that. And now that the valves are out I would lap them in and then you need to adjust the valve clearances. Addicted2boost says this is a PITA but I just consider it as time consuming. I don't know how mechanically incline you are but if this is over your head I would let the shop do it.

 

If you have over 100K miles on the engine, plan on keeping the car or want it done right the first time, then let the machine shop do the work. Trust me, it may be expensive, but when it runs right (assuming the rest of the car is up to par after the fuel pump) you'll be glad you did. If you're strapped for cash, hold off on doing the fuel pump but don't go past half throttle. Besides, think about this for a moment... Lapping 32 valves... Having to R&R the 4 cams to adjust valve clearance. Making trips to the dealer to buy shims, waiting on parts. It's money well spent having someone else do this.

 

Thanks very much for all the help. In response to Bob; there is not any sign of warping of the head. Now with that said, would you all recommend/agree that I should just leave it as it and reinstall with the new gasket? Since, as mentioned, there's not warpage I assume we're in good stanfing, correct?

 

Sign? Warping may not be bad enough to visually detect. But since the headgasket failed, you have to wonder why. I would go ahead and have a machine shop measure the heads for warping, check for cracks, clogged coolant passages, etc. If they are OK, then just put them back on.

I used to be of the mindset that as long as I had an engine apart I might as well do a full rebuild. But while it seemed like I should "renew" an engine as much as possible, decking blocks, shaving heads, boring cylinders, grinding valves, etc. is all changing the original design parameters and not always for the better. Now I lean toward doing minimal machine work as necessary. But I still would not put an engine back together until I had determined why the headgasket failed in the first place or at least ruled out every part that I had access to inspect. Perhaps it was a defect in the gasket itself or it wasn't torqued down properly or some other system malfunction causing abnormal combustion. Hopefully its something simple like disconnecting the NOS

 

You can just put on new headgaskets and let the rest go. This is what proably most members do when they have a bad headgasket.

 

Forgot to mention when you get the headgasket get one for an 04 xjr. It should be a MLS, multi layered steel, headgasket. It will be for a 4.2L engine. Don't get the Lincoln LS headgaskets because I found that the water ports are smaller and may cause overheating.

 

Hi guys,

Thanks for all your help. I've been out of state away from home so I hadn't have to change to work on the car. As for the head gasket, I've ordered and received the eurospare gasket kit categorized under my car in a specific search on the website; therefore I assume it is only the one for 4.0 instead. Anyone have experience with the eurospare? Also, I don't know how I could ever have missed on mentioning this; I went over my original post to make sure you all have helped answer all the questions I have, but only to realize I didn't even mention there my main concern. As I have the camshafts locked and during the attempt to loosen the exhaust sprocket on the passenger side, that exhaust camshaft moved and rotated due my idiot mistake of not having the lock tool on tight. I saw the whole movement and stopped immediately, only to get hit with the camshaft moving the opposite direction as I let loose of my opening tool because at this point it had loosen enough to slip free on any hold down; possibly from the tension of the chain forcing it back. It was the only one the moved/turned; the other one on top didnt move at all because it was correctly tightened down. The cam, however, didn't rotate a full turn. After that I kind of just eye-balled it and moved it back to where the cam flat of that particular cam is aligned with the top one that didn't move a bit as I originally started out with. I didn't have anything marked at all at this time so I only did what I can based on memory and visually. My question is: Am I basically screwed here with my timing?

 

For the headgasket set from Euros pare you should be ok. The reason most of us suggest the 4.2L headgasket is it is MLS. The 4.0 gasket will more than likely be a fiber gasket. It will be the same that is on the car now but the MLS is a longer lasting gasket.

As for the cam timing you don't need to worry about that until you reinstall. Download the " Engine repair course code 168" from Jagrepair.com. It will give you info on reinstalling the heads and timing the cams.

EDIT: we never discussed this before, do you have the updated tensioners? If not change them now!!!

 

Well that's a huge relief to hear that. Thanks very much for the answer. As for the tensioners they are the updated metal ones. Thanks again to all. I will keep the update on the progress. Any more suggestions please do chime in.

 

Ok guys so here is an update on the job. I couldn't get the time I would like to work on it so it took me long than expected. Anyways, I am putting everything back on, following the "Engine repair course code 168" from Jagrepair.com advised by Bob Roy; thank you by the way. As I get to doing the valve timing check by turning the crank 3 revolution to make sure the cam flats aligned; I couldn't turn crank but just barely budging it. It is very very hard to turn and I don't want to fo anymore than I have and then break anything. The crank lock tool is out of the slot of the flywheel; I've followed all the steps I recall. Did I screw something up in the process? Please advise.