Major XK engine work.
#42
The process for installing seats in aluminum heads consist of heating the heads to 300 or so degrees, freezing the new seats, then a guide is installed in the valve guide , and the seats are installed on a drift and hammered into place.
If, there is not enough room in the chambers for over sized seats, then the pockets for the seats will have to be welded up then machined, for the installation process.
You need to find a competent shop to do a proper install. If the heads have to be welded, make sure the welder is competent and does a pre-heat of the heads.
Don't cheap out on this, either do the seats right or just replace the heads, otherwise it will come back and bite you in the ***.
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GordoCatCar (09-17-2020)
#43
Similar experience-just sharingI share
I share your reticence about posting on the internet, and I have no advice to offer. I wouldn't have replied to your post except that I have experienced the same engine damage as you, and it brought to mind my whole experience with Jaguar engine repair. I thought I would share it with you, for what it is worth.
First, some background. I have a '99 XJ8 and a'97 XK8. The former was purchased almost new many years ago and has been kept in excellent condition. Until recently, I have never had any problems with it. The latter was purchased sight-unseen on the opposite side of the country for a bargain price, and I definitely got what I paid for. However, It was been totally refurbished and is now in excellent condition.
Here is my story.
When I purchased the XK8, the engine failed almost immediately. That is where I started using my own judgment when I should have listened to my mechanic. I opted to have the engine rebuilt. My mechanic strongly advised against it and advised replacing the engine with a good, used one. My response was "Why would I do that? I would only be purchasing someone else's problems. With a rebuild, I would essentially have a new engine."
The rebuild was defective. The milling was faulty, and the engine was sucking coolant into the cylinders passed the head gasket. I was right back where I started. I could have insisted on having the work re-done, but for personal reasons decided not to do so. However, I got out of the situation at no cost. I then took my mechanic's advice and purchased a used engine with low mileage form a Jaguar dismantler with whom I have been dealing for many years. He stands behind what he sells. My mechanic replaced the timing chain. I think everyone knows that is essential on this vintage engine. Jaguar now sells an upgraded version. The timing chain, guides, etc. were replaced. The engine was installed. I have been driving the car regularly with only minor repairs ever since. I do not regret my purchase purchase. In fact, I love the car and get compliments on it even though it is 23 years old. But I do wish I had listened to my mechanic.
The XK8 is now my daily driver. As much as I love the XJ8, it has seen only infrequent use since I finished all the work on the XK8.
Fast forward. My XJ8 has never had any serious problems, and I have maintained it with scrupulous care. Nevertheless, things happen. About a year ago, I drove it into town and parked it in a shopping center parking lost. No problem. When I came out of the store and restarted it, it immediately ran extremely rough. I limped to my mechanic's shop. He put a scope into the cylinders and immediately saw exactly what you found upon dismantling your engine. A valve seat had lifted out of the head. I would not have thought something like that was even possible. Don't ask me how a valve seat lifts out while the car is sitting in a parking lot, and that is why your post caught my interest. Apparently, it happens.
I immediately contacted the same dismantler as before. Note, considering the age of the car, I did not think the prospects for finding a decent AJ26 (the AJ27 went into production after my car was build) would be good. To my surprise, the dismantler had an AJ26 with acceptable mileage, which he sold to me for $1,500 without any shipping costs. (He is fairly near my home.) For various reasons, I have postponed installing the engine. However, my mechanic has it at his shop. I will probably have it installed next month. My mechanic will, as before, replace the timing chain, guides, etc. and, then, swap the engines. Estimate is around $2,000 out the door.
I am a die hard do-it-yourselfer, but rebuilding a jaguar engine is something I could not possibly do. With my prior experience, I would not even have one rebuilt by a mechanic. It is very expensive and lots of things can go wrong. Fortunately, I got out of the rebuild at no cost. Needless to say, taking the car to a Jaguar dealer is out of the question. I don't even know anybody who can do that.
I have nothing but admiration for your courage in doing all this diagnosis and work your self. I wish I could. Best of luck in your project.
First, some background. I have a '99 XJ8 and a'97 XK8. The former was purchased almost new many years ago and has been kept in excellent condition. Until recently, I have never had any problems with it. The latter was purchased sight-unseen on the opposite side of the country for a bargain price, and I definitely got what I paid for. However, It was been totally refurbished and is now in excellent condition.
Here is my story.
When I purchased the XK8, the engine failed almost immediately. That is where I started using my own judgment when I should have listened to my mechanic. I opted to have the engine rebuilt. My mechanic strongly advised against it and advised replacing the engine with a good, used one. My response was "Why would I do that? I would only be purchasing someone else's problems. With a rebuild, I would essentially have a new engine."
The rebuild was defective. The milling was faulty, and the engine was sucking coolant into the cylinders passed the head gasket. I was right back where I started. I could have insisted on having the work re-done, but for personal reasons decided not to do so. However, I got out of the situation at no cost. I then took my mechanic's advice and purchased a used engine with low mileage form a Jaguar dismantler with whom I have been dealing for many years. He stands behind what he sells. My mechanic replaced the timing chain. I think everyone knows that is essential on this vintage engine. Jaguar now sells an upgraded version. The timing chain, guides, etc. were replaced. The engine was installed. I have been driving the car regularly with only minor repairs ever since. I do not regret my purchase purchase. In fact, I love the car and get compliments on it even though it is 23 years old. But I do wish I had listened to my mechanic.
The XK8 is now my daily driver. As much as I love the XJ8, it has seen only infrequent use since I finished all the work on the XK8.
Fast forward. My XJ8 has never had any serious problems, and I have maintained it with scrupulous care. Nevertheless, things happen. About a year ago, I drove it into town and parked it in a shopping center parking lost. No problem. When I came out of the store and restarted it, it immediately ran extremely rough. I limped to my mechanic's shop. He put a scope into the cylinders and immediately saw exactly what you found upon dismantling your engine. A valve seat had lifted out of the head. I would not have thought something like that was even possible. Don't ask me how a valve seat lifts out while the car is sitting in a parking lot, and that is why your post caught my interest. Apparently, it happens.
I immediately contacted the same dismantler as before. Note, considering the age of the car, I did not think the prospects for finding a decent AJ26 (the AJ27 went into production after my car was build) would be good. To my surprise, the dismantler had an AJ26 with acceptable mileage, which he sold to me for $1,500 without any shipping costs. (He is fairly near my home.) For various reasons, I have postponed installing the engine. However, my mechanic has it at his shop. I will probably have it installed next month. My mechanic will, as before, replace the timing chain, guides, etc. and, then, swap the engines. Estimate is around $2,000 out the door.
I am a die hard do-it-yourselfer, but rebuilding a jaguar engine is something I could not possibly do. With my prior experience, I would not even have one rebuilt by a mechanic. It is very expensive and lots of things can go wrong. Fortunately, I got out of the rebuild at no cost. Needless to say, taking the car to a Jaguar dealer is out of the question. I don't even know anybody who can do that.
I have nothing but admiration for your courage in doing all this diagnosis and work your self. I wish I could. Best of luck in your project.
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#45
Thank you for admiration , although unnecessary.
As o have said I have 35 years of engine building experience. 20 of them working on and rebuilding both ferrari and Lamborghini engines that I own.
An engine is still just a basic engine after all the electronics are taken away.
my son has his own engineering workshop so most of the milling/lathe work over the years are done by us.
New heads have been sourced and rebuilt and this weekend I will be re assembling the unit. The heads were measuring out of spec so I thought it's not worth taking the chance of any internal damage to the casting.
So if there is any specific section anyone would like me to post pictures of or give notes, please feel free.
Thank you again folks 🤗
Last edited by SBS; 09-17-2020 at 02:23 PM.
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#46
#47
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#48
#49
#50
#51
#52
Lower radiator hose to VIN B02896 - C2P2159. From VIN B02897 - C2P11448
Last edited by Sean W; 09-17-2020 at 05:00 PM.
#53
Material differences
Interesting as I have never seen seats pushed out like that. Assume the overheat and the material difference between the head and seats contributed to it. Looks like one of them ruined the head. Can the heads be rebuilt or are they toast. Good luck and keep us posted. I burned a valve in my V12 and pulled that apart and salvaged the head . At my age now I don't think I would tackle your job.
I hope there is an updated material that would prevent you from doing this in another 70k miles!
Thank you for the very detailed repair as you go pictures!
Alan.
#54
Hmmm
Hey, I dont usually post in depth things on the internet. I find forums can be a very toxic place, some people would start an argument with them selves. I don't want this being one of them please.
However I though there might be some genuinely interested partys that might like to see some pictures along with progress reports over the next few weeks.
Two weeks ago my 2008 4.2 XK was over heating. That was down to the water pump which was easy enough.
So after two days of driving the car suddenly gave an over heating warning light on the dash. I was maybe a mile or so from my home, so I drove slowly and the light went of. The engine was running great, no noises ....nothing. Then once on my drive the engine just stopped....nothing. It would not re start so I thought I would let it cool down over night before I investigated. The next morning the car struggled to start and when it did it sounded like half the cylinders were running. Strange because the engine sounded great up to the point of when it stopped.
Next day, I did a compression test and on both cylinder heads the last two cylinders were not registering. Mmm, two blown head gaskets maybe.
Started stripping it down and eventually rook the left head of, dam. Valve seat pushed out and has chewed the material around were it sits. Some thing tells me inside that the right head will be the same. It is.....in fact it's worse
Guys and girls, I will keep you updated and pictures posted for your entertainment.
However I though there might be some genuinely interested partys that might like to see some pictures along with progress reports over the next few weeks.
Two weeks ago my 2008 4.2 XK was over heating. That was down to the water pump which was easy enough.
So after two days of driving the car suddenly gave an over heating warning light on the dash. I was maybe a mile or so from my home, so I drove slowly and the light went of. The engine was running great, no noises ....nothing. Then once on my drive the engine just stopped....nothing. It would not re start so I thought I would let it cool down over night before I investigated. The next morning the car struggled to start and when it did it sounded like half the cylinders were running. Strange because the engine sounded great up to the point of when it stopped.
Next day, I did a compression test and on both cylinder heads the last two cylinders were not registering. Mmm, two blown head gaskets maybe.
Started stripping it down and eventually rook the left head of, dam. Valve seat pushed out and has chewed the material around were it sits. Some thing tells me inside that the right head will be the same. It is.....in fact it's worse
Guys and girls, I will keep you updated and pictures posted for your entertainment.
#55
Wow. I’ve read many posts that the 4.2 Al engine has no tolerance for even 30 sec of overheating. I regularly ck coolant level and specific gravity but these pics have me spooked. Also that factory temperature gauge is unreliable and a numeric temp gauge is needed. So, how big a deal is installing one? What kind? Where available? Who’s done it?
Thanks
Thanks
On the 4.0 it moves off the middle at 115C which isn’t really all that toasty, I’ve heard on the 4.2 it stays in the middle till 126 which is a bigger problem. Some aluminum motors are just tanks when it comes to overheating (BMW M62) and others just aren’t as forgiving.
Last edited by xalty; 09-17-2020 at 08:17 PM.
#56
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#59
#60
So X150 owners, do not use the green stuff unless a stop gap situation.