Hello hive mind. So I have a blown head gasket on my 2017 F-type V6 (specifically the 4, 5, 6, cylinder bank only). I've been doing lots of research on what it takes to replace one and it seems like an absolute bear of a change on this car. With exhaust manifold bolts nearly inaccessible, a VVT system that might require removing radiator to access all the chains for its removal, putting the chains back with proper timing, etc this is way more work than the head gasket i've done before on a 1994 ford explorer and simple inline 6 of an old jeep. Both didn't have variable valve timing. So, is this repair even doable in the car or should the engine be dropped? I don't have the capabilities/room/equipment to drop an engine. So if the engine should be dropped, I would need to have a garage work on it and that is ~$8-11k.

I am also afraid that even after I do all the work including having the head remachined and all appropriate parts walnut blasted clean, it may still not work because this fail was from an overheated engine. So if I had to drop that much time/money, i'd rather just get a new engine. And at that point, upgrade to a v8? (is that a thing?)

For everyone that is going to ask, yes, it is 100% blown. Low cylinder compression and the coup de grace is the attached video of coolant leaking into the cylinder after pressurizing the system.

Thanks!

 

Depending on your level of wrenching ability and tools, it's really not that challenging of a job. Naturally that's all perspective, but I was able to remove the cylinder head with the engine insitu.

See my post here:
https://www.jaguarforums.com/forum/f...emoval-271413/

Personally, the bigger question is why did the headgasket fail? That's not a documented frequent failure on the AJ126, unless the car loss coolant and overheated. Would you have any addition context prior to the failure?
In any case, it's just a situation of troubleshooting. It's too soon to tell what the issue is until you start tearing it apart. As with anything, there's no real easy answer here and you'll have to figure out time vs $$ for your case.

If a replacement engine was super cheap <$3k and abundantly available with good reputation, then I think an engine R/R could be considered. But at >7K plus, I would do whatever I can do figure out the issue and see what's salvagable. It could literally be just a HG R/R which would be a couple hundred bucks or something else much worse. Only opening things up can tell you.

 

Yup. Lost coolant pump and overheated and ran overheated for a bit. Had a coolant hose also fail, which makes me think all the hoses are compromised.

So removing the exhaust manifold wasn't a pain? Did you access the bolts from the top or underneath because I can't imagine getting to them from on top.

 

Ah, I see. I'm sorry to hear about that. I would also think the hoses are nearing or at their end of life.

Both top and bottom utiilzing various wobbles, extentions, sockets, etc. It's not cake walk, but it wasn't crazy challenging either. I soaked the nuts in penetrant the night before and it wasn't bad. Once you remove the padding/covers there's more room to work with.

Since it overheated, there is a chance the head or block could be warped, but then again it could be within tolerances that a new HG would be fine.

If you have access to a bore scope, I think that could give you some useful data for a determination in which direction to take. If the engine overheated so badly that there's cylinder wall scoring, then yes, perhaps an engine R/R may save you some time. But if your cylinders are still clean, I would advised atleast removing the head and put a straight edge of the head/block. You may have just lucked out and it's all good, then put on a new HG, probably some timing components depending on mileage, and be on your way. Just food for thought.

 

After working on my XJR with the 5.0L SC engine I found that removing the nuts on the engine mounts and then placing a board under the oil pan it's possible to not only lift the engine up but you can jack on one side and tilt the engine. This made a massive difference when I was working on the passenger side.

I did not remove the head but did remove and replace my injectors and plugs. Access was nearly impossible until I got the engine up and tilted a bit.
.
.
.

 

Looking for scoring is a good idea. I'm looking at the 3 cylinders and in my opinion, they look to have some (see attached images/videos). It doesn't look "terrible", but these are high precision machines and prognosis isn't good. Second opinion?

You have a great write up on the process. Thank you for that. Also, do you think it would be possible to remove the head with the exhaust still attached? That could save some time/effort.

Side note, I had to replace fuel injectors before and like you I had one that refused to budge. I ended up attaching a car jack to the removal tool braced against the frame and literally jacked it out. That was fun...