It's confirmed. I need a new engine. Rumour has it i have holes in the pistons (apparently that'd a bad thing).

It's been decided I will stick with a Jaguar engine (rather than the LS2... Can't get the LS2 to be as smooth or quiet as the AJ)

It's been decided I will grab one from the junkyard, 4.0 or 4.2 I don't know yet... still not sure about the whole 4.2 thing (any links would be nice).

Aside from the obvious problems with the AJV8, what should I have 'repaired' before I put it in the car?

Is it worth taking the time the clean the new engine and the engine bay before installing it?

Now all I need to do is find another one as I already missed the boat on three. Wish me luck.

 

engine mounts, rasberry filled, probably needs new ones (LH tears easily on go, RH side gets beaten off acceleration). I'd inspect carefully the lower radiator hoses, look for leaks on that power steering line and oil cooler line too. Idler and tensioner pulleys maybe. Others with engine-out experience will give you some more items to look at while there's a big hole where the heart was.

 

I would definitely get an engine to match what was in there. There are too many systems set up for that engine to switch them succesfully. Since this series had the nikasil engines with the bad water pumps and secondary tensioners, I would be sure these thigng were replaced and try to determine if the engine has compression.

 

Not sure what you mean by smooth in the LS2, I think the engine idles very nice, but it depends on the tune and I will admit the LS2 injectors are a tad noisy, but man you cannot beat the engine, it takes mods easily and revs up quick, oops sorry got off topic.

I would replace with a 4.0, but there is a thread about swapping a 4.2 with a 4.0, but I cannot see doing all that for 4 ponies.
Look for telltale cracks near water jackets and the heads, get a magnifying glass to help you look, check tensioners and timing chain guides for abnormal wear. If the engine is over 125k miles or unknown mileage, I would rebuild.

Take along a socket that fits the hub bolt and breaker bar, then take the plugs out and check to see if the engine turns over smoothly.

 

You have the AJ26 engine in your '98 and most of those are getting a little long in the tooth. I wish you well on finding a good one. Converting to the '99 to '03 AJ27 will produce many more engines to choose from but the swap will be more complicated. Basically, you will have to back date the 27 back to the 26. If you are going to have the work done by someone the conversion is going to add significantly to the cost.

Here are a couple discussions on the subject:

AJ-V8 Engine compatibility question - Jaguar Forums - Jaguar Enthusiasts Forum

Quick Reference: Swap your 4.0 block with a 4.2 - Jaguar Forums - Jaguar Enthusiasts Forum

 

How did you get holes in your pistons?

 

Holes in your pistons?

Either get the correct engine or go for the LS crate motor. Upgrading to a later model engine will prove troublesome. Enough trouble that you'd have wished you upgraded to the LS.

 

It just occured to me that if the only problem with the engine is holed pistons, replacing the pistons woudl be the cheapest way to go. The question is what led to the problem? This needs to be determined before even changing the parts over to a new block. I rarely hear of holed pistons since the days of fuel injection. In the old days of carburetors, there were a lot more holed pistons as the cause is often lean mixture and overheated piston tops. Carburetors diod not have a check engine light to warn of improper mixture.

 

Exactly.

Could dirty injectors do it?
Too much air, not enough fuel?
I would have thought there would be some fore warning if the mixture was out enough.
On the 2-stroke motorbikes i've owned in the past, they weren't really able to run with a holed piston, but a V8 might be able to run for some distance in limp home mode, so i wonder if some petrol could have dribbled through the hole in the piston and in to the oil supply.
If droplets find there way to a small end or big end bearing/shell, could they do some damage to those parts?
Even if the holed piston cause is found, i'd flush the engine oil.

 

Holed pistons can happen for a number of reasons, but I would think a headgasket failure would be the number 1 cause, because water does not compress.
Dropped valves will also cause holes,as will having the timing way off.

 

As a little backstory, I had the tensioners go on me. When I bought the car two years ago dude produced a receipt showing me that they had been replaced so I didn't worry about them.

One day I was cleaning out the shed so I had to move the car from the driveway. I backed it out onto the street, parked it and turned it off. I went to pull it back in again that evening, engine wouldn't even started. The starter would do it's thing, but nothing.

I've been led to believe that I may have taken a few trips after the problem manifested itself, which may have exacerbated the problem(s). Chances are I also have valve damage and possible liner issues. My go to guys have said the most economically viable option is just to replace the engine.

The question is:
Do I replace it with an AJ26 and hope I don't need to rebuild it (would defeat the purpose).
Do I replace it with an AJ34 and pay a little extra for the work?
Do I replace it with a GM LS-series engine and risk losing the silkiness/fuel economy of the AJ28?

Thanks Matt.

Any suggestions on how I can determine the status of the nikasil issue? I'm responsible for finding the engine and I don't think the junkyard would let me tear it apart out there. New water pump and tensioners are already purchased.

The LS engines I've taken out have had the rougher, muscle car feel to them rather than the silky smooth, no-vibration purr of the AJ26. Maybe I've just been unlucky enough to get 'otherwise equipped' Vettes and f-bodies out and about.

Based on my limited knowledge, it almost seems as if it's easier to swap in a 4.2 instead of an AJ27. Given all the risks I'm not equipped (or likely not permitted) to check in the scrapyard, this may be the way to go... if one can be found.

I just fear the information has been over simplified.

 

Melted piston with hole would be extreme lean condition
Blown head gasket maybe shattered piston but I would think it would hydro lock causing a bent rod....

 

How many miles has your current engine done fedoraja1?

You should always be aware that i may well be talking out of the wrong end of my body whenever i post, but i'm given to understand that if the chains jump, the valves can make contact with the pistons, which could explain the holes, and the likelihood of bent valves.

Would it not be feasible to get a replacement AJ26 from the breakers, and fit the rods, head, pistons and valves to your current engine?

It's almost a rebuild, but there's no telling if a breakers engine doesn't have it's own underlying time bombs, and to complicate it further with another unknown and different engine seems like as much of a risk/workload as any other option.

 

180 000km on it.
With the valves, that's the consensus: pistons + valve = hole.

Regarding the rebuild vs. the scrap... that's a million dollar question.

My guy quoted me about $6000 to rebuild my original engine.
If I get a piece from the scrapyard, they will guarantee it - I will have my guy give it a look over, if it works out, I'll use it, if not I'll send it back. I can also cannablize the parts, I'm sure.

 

Just a liitle more that others may be able to correct me on:

If the head gasket has not blown, you may be able to get away with not replacing the rods in your current engine.
My physics/chemistry was never fantastic, but iirc, water will sink to the bottom of oil, and petrol floats to the top of water, but i don't know what it does in oil.
If petrol floats to the top of oil, then draining the engine oil into a clear container and leaving it to settle for a day may tell you if you have water/petrol in the oil.
If there's no water in the bottom of the oil, you may not have bent a rod (due to compression of the rod instead of the water), and you might be able to just (Just???) swap pistons, head and valves.

Please, somebody pull this logic to pieces (seriously)

 

Just noticed your last post, after writing my own.

180,000km is just shy of 112,000 miles.

Chances are you can find an engine with similar mileage.
Personally i'd swap for another AJ26 (saves butchering bits to fit from a different type of engine), fit the tensioners and water pump (is the thermostat housing plastic?) and hope for the best.

 

Not that it's important at this point, but water and oil form an emulsion with the engine running, a light brown foamy mess, not a good lubricant. Gasoline is totally miscible with oil and the result again is a poor lubricant.
I don't understand the negativity toward the AJ26 nikasil engine. Changing the water pump and tensioners is a small job, and many have suggested that the nikasil liners are superior if in good condition.

 

Thanks RJ, at least now we know.
So much for that theory.
If i can consider myself to have had any luck with my own car, it's that i have one of the very last of the Nikasil's, build date 19/07/00.
It's been said many times that a good condition Nikasil is probably better than a steel lined engine, due to the Nikasil resulting in slower bore wear and better compression for longer.
If fej can find a good AJ26 with good compression on Nikasil liners he may well have had the best result he could hope for.
Since any replacement engine will presumably arrive in a crate/on a pallet, he may want to consider replacing the primary chains and tensioners before it's installed.
The question is whether he can stand the extra cost (labour should be as minimal as it gets with the engine already out), and whether it invalidates any gaurantee he might get with the replacement engine.

 

That's the key: in good condition. From what I've read, nikasil is the superior of the liners... just leaded fuels tend to kill it.

And if there's an issue with the liners in my current engine, I understand they are hard/expensive to replace. Rumour has not just anyone can resleeve an engine...properly.

 

That's the plan. I have a (nearly) brand new thermostat housing and water pump on the dead engine.