After 23 years and 187K+ miles, the car reports an "Engine Fault" and shortly after a "Poor Vehicle Performance" (and then alternates between them) accompanied by weak acceleration and intermittently rough running performance. Shop reports misfires on several cylinders and a compression check reveals at least one cylinder with zero compression.

Question: a number of sources report remanufactured engines for around $2500+, for example, AAA Engines in southern California, though I'm sure there are others. Does anyone have (good) experiences with either them or some other supplier?

The car has been a joy and was a daily driver for almost 20 years before entering retirement as a backup / collection vehicle. A transmission replacement/rebuild was expected to occur soon. Replacing either is worth more than the car (which is in good shape otherwise especially given its age). Sentimental reasons motivate wanting to keep it running but perhaps the time has come to send it to the farm. But before concluding that want to find out what other options might be available.

Thanks for any guidance / pointers.

Rob Gingell
'66 S1 E-Type FHC 4.2
'97 XK8 (maybe for a while longer)
'14 F-Type Coupe R

Hmm... What would be a reason for zero compression, I wonder?

My 2002 has 210k miles and counting. The engine is still strong. When I first got her,,, she had a dropped valve seat on the driver's side that caused all kinds of strife... Thanks to the unusual level of support here, I changed the cylinder head (first job like that ever for me) and it's been love, since. A lot of the misfiring disappeared with that fix,,, all the rest soon after.

I'm amaaaaazed at how strong the engine is and was at 200k... Amazingly built and engineered...

I would look to the cause of the problems and git dirty... That's just me. You'll get all of the support you need here, some quality YouTube and reading. What do you have to lose,,, other than a little knuckle skin...?

As Jay says, it cost's you nothing to open up the engine to see if you can determine the issues. It does sound like a valve issue, as those are common. Remanufactured heads are available,or you can have them done locally. Expect $500/head, plus add another $500 for gaskets, seals, coils packs, plugs, etc..... There are really good video's and threads on head removal and replacement. If the cylinder walls look good fresh heads may just do the trick.

Another option is a used engine, but you could have all the same issues.

If you think a trans rebuild is also due, then you might consider an LS swap, as seen in a recent thread. More money, but in total probably not far from what an engine rebuild and trans rebuild on the Jag would cost.

Assuming here that you will be doing most of the work. If you have to pay to have this done, either way, ti can get costly.

Something that was and has been really helpful with misfires without going out and purchasing a bunch of new coil packs was ONE layer of self vulcanizing tape around the boot of the coil pack plug. One coat because refitting the coil packs with more than one is toooooo tight a fit... Once placed on a clean boot, layered upon itself, it doesn't move!

Also, unless it's overly daunting, I replaced my Cylinder Head myself and it didn't cost more than 350 total,,, if memory serves me. It was the guys here that walked me thru it and it turned out to be not too hard at all. For a used head, valve lapping isn't impossible.... For me,,, Getting the VVT right again was/IS a different story. Tough! CEL has been on since, smh... Bit she runs sweetly.

And yeah? How wrong could the trans be?

Don't let her go...!

It would be really helpful to have more info on how many (and which) cylinders have zero compression, because that will give much more insight into what is going on. There does seem to be a disconnect between the idea that you have cylinders with zero compression and that the rough-running is intermittent - I'd expect the rough running to be constant, unless you have a valve that is sometimes, but not always, sticking.

^^ Agreed that seems odd.
Did these symptoms come on suddenly or has the performance been deteriorating for some time?

I'm with the others and would definitely dig deeper before passing the death sentence, particularly if there's a sentimental attachment.

Thanks for the thoughts and observations so far. Apologies for not responding to the queries sooner, a short trip interrupted diagnosing things further, but have gathered more information.

The original faults leading to the Engine Fault + Poor Vehicle Performance were misfires on 4 cylinders (P035x codes) for cylinders 8, 5, 3, and 2. The shop also found some of the plugs very gummed up with oil that appeared to have been entering the cylinders from above and had been going on for in their estimate several thousands of miles, this on the right bank of cylinders (1-4).

What I inaccurately described as "no compression" was really low compression on cylinder 4: initially getting measures between 30 and 50 when dry but with oil wetting coming back up to 130 or so. The full set of dry readings 1-8 are 115, 155, 150, 30-50, 130, 155, 105, 130.

The shop hasn't dug any further than this pending finding out what direction I want to go in. They observe they could replace the coils/plugs on the ones reporting misfires (or do them all as all but a couple are original), renew gaskets to deal with the oil seepage, though that would leave the rings on cylinder 4 and perhaps as yet unknown issues remaining given they only spent about an hour going this far. They did wire brush off some of the plugs while they were at this which has had the effect of temporarily restoring smooth operation and no faults but neither they nor I expect that to continue for long. And of course there's the rings/compression issue with cylinder 4. The shop prices for renewing coils, plugs gaskets and such are more than double the likely value of the car, but it's a dealer so I'm sure the price can be reduced.

Some of the comments note the opportunity to roll up my sleeves and get into the car. I do that some with my E-Type and other machinery but am full up on projects and taking on another, especially one stretching my capabilities as much of this is too much. Still, the for-the-moment smoothly running car does make me want to explore what's really needed further, perhaps at a less expensive shop.

The mechanic who did the work spent a good bit of time chatting with me about the options and about the engine and what was going on when I was experiencing what I thought was rough balky performance and the limp home mode the engine was falling into. The AJ26 is a pretty remarkable piece of engine engineering, kind of amazing how much thought has gone into fault management and detection especially compared with what I'm used to being hands on with like the XK or farm equipment.

If this extra description provokes other thoughts / recommendations be grateful to hear them. Thanks for people's contributions so far.

The oil in the spark plug wells (which I assume is what you mean, rather that the tips of the plugs being affected) is a common problem, as oil gets past the little gaskets at the top of each well. This can cause a misfire, as I know from experience. Just get the camcover gasket replaced - although still expect a bit of leakage, as I seem to have.


What conditions was the compression check done under? Hot or cold? These cars can suffer from bore-wash where compression is temporarily lost if the car is started cold and then turned off again before it gets up to temp.
Personally, I'd clean up the plugs and coils, removing any oil or gunk, clean the oil out of the plug wells and then see how it runs. If that improves things then invest the time and money to change the camcover gaskets.

I have to say, thoughts of engine swaps seem very premature at this stage.

+1

Don't rush to replace.

BeaUTifulll! Plus plus on all that ^^^^^

I'm sorry. But I would be very careful about following the course of any mechanic with my machines... I'm not passing judgement on your guy,,,, but what EXACTLY is going on in the heads of others, what motivates the things they do and say at any given time,,, well let's just say,,, the grains of salt could fill a salt shaker. I always remember they often have an interest that isn't actually in line with my own.