Went to start my 04 XJR after work this evening. The starter turned, the front of the car twisted down on the left side, thought I heard a noise then nothing. Tried again and the starter tries but cannot spin the motor. Felt like something let go in there. Ran great when parked this morning. 176k on the clock. Time for goodbyes?

Thanks,
Kevin
Milwaukee, WI

 

Was it cold? Take a look at these threads:-

https://www.jaguarforums.com/forum/x...engine-110573/

https://www.jaguarforums.com/forum/s...erally-173975/

 

Huh, hydrolock, that’s a new one. Might be the case. Was 3 degrees on the way into work this morning. It spent the day in a heated garage but I suppose there could be water in the cylinders now.

 

Yep, water in cylinders. Just a few ounces but enough to stop the pistons from reaching the top of their stroke. Back to running normal. Going to let it idle after a run in 0 degree weather from now on.

 

You will be very fortunate if you haven't bent a connecting rod. Maybe just trying to start doesn't have enough oomph to do that, but ingesting water into a running engine does Very Bad Things.

 

I think with zero inertia in the rotating assembly, there is a very low risk of bending a conrod. An engine under power is a different story.

To be safe, a compression test can help verify that none of your connecting rods are bent.

 

wfooshee the engine does not suck in water. Did you read the links? It's a very strange set of conditions only seen on SC cars and with very short running times. It appears to be ice forming in the intercooler system that goes into the engine causing a short term hydro lock.

Here is the explanation;

What happens (and it took me 6 months of researching to believe that it's even possible) is while driving, airborne water vapor condenses and becomes ice, primarily in the intercoolers and tubing. After shutdown, residual engine heat melts the ice which then trickles down the intake tract into whatever cylinder happens to have it's intake valve open at the time.

At next start up that water, or ice in your case as it refroze, causes the engine to hydrolock. If you're lucky, warming the engine and cranking it with the plugs out will clear the residual water with no other harm done. If you're unlucky, the connecting rod on the affected cylinder(s) will have been bent.

Really rare to happen too.
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I did see where the water was coming from, but any time the compression stroke is interrupted hard enough to stop the engine, I'd wonder about the conrods. As stated above, cranking speed may not have the inertia to actually do damage.

 

I believe this has just happened to my S-Type R as well. My scenario and symptoms seem to line up very well with the other people in those two linked threads:

- Car fired up perfectly happy in the morning at ~5°F. Battery cranked the car with no signs of weakness, car has not had any mysterious warning lights or other signs of a weak battery, starter has never shown any weakness or seizing prior.
- My commute to work is basically 25 minutes of 60-75 mph highway cruising. Didn't give the car any hard or aggressive throttle at any point due to the very cold weather.
- I pulled in, shut the car off for about 9 hours, nothing out of the ordinary.
- I come back out to the car, ambient temperature about 18°F, car cranked for about 1-2 seconds then stopped turning. Every crank afterwards had less and less movement until it sounded like it was entirely seized.
- My boss helps jump the car off, no change in cranking at all, starter still sounds like its fully engaging but the motor isn't turning at all. Connected multimeter drops to ~9 V when starter is engaged, was reading ~14.7 with jump connected.
- Came back the next day when the temperature was significantly warmer (~34°F) with brand-new battery as I had figured the battery had dropped a cell due to seeing a significant voltage drop with just the interior lights on, same exact issues as before, no change.

My work is letting me pull the Jag into a heated bay, so I'm going to pull the plugs and check with a borescope to see if any water is in the cylinders.

If this cold weather issue is the culprit, this is a huge bummer as I have an XJR that I'm rebuilding as a winter runaround. This being a known issue would make me not trust the car at all once the temperatures drop well below freezing.

 

I hope you have the problem that autocad23 had. That would be a great outcome.
This is just an odd thing to happen and until read the explanation above I did not believe it could happen?

Can post back with the results? Sounds like it might be the same issue.
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Looks like water in the cylinders causing hydrolock was indeed the cause! I pulled all the plugs and found that 4 of the 8 has water on the electrode. I also ran a borescope down into the cylinders and found that 4 of the 8 had water in them, with one so full of water that it was up to the spark plug hole.

I turned the engine over on de-flood mode and was astonished at how much water came out! It is amazing how much ice that intercooler held, yet the car ran exactly as I expected it to.


I haven't driven the car much since putting it together a few hours ago as the ambient temperature dropped below 15 F when I finished up, so I just parked the car outside at my work since I didn't want to chance driving it 30 minutes back home and risk having to do this again.

On first start and when driving it over to the parking lot, it definitely doesn't run as smoothly as it did before, feels like there's a very slight occasional stumble at idle with no load, similar to how it felt before I replaced all the ignition coils 20k miles ago. Perhaps a few of the spark plugs have had their gaps reduced due to the ice in the cylinders, or maybe it just needs to be driven for a bit. It doesn't seem to be running poorly though, so that's good!

 

That's a shocking video and a LOT of water!
Glad I posted what I did because your problem sure sounded like what you found.

I bet with a bit of driving all will be well too! It just so rare I don't know that I would worry about it?
I mean your maybe the 2nd or 3rd person to report it.
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I would not have believed it if I hadn't seen it! Thanks to all the posters for this heads up!