I think the EGR is after the SC (can't recall and have never had mine apart), so can't really be part of this.

 

I was the one who mentioned the engine cover. No one who has had the water problem has mentioned whether or not their engine cove was off or on.

The engine or charge cooler cover is intended to insulate the charge coolers from heat that gathers under the hood when the car is stationary essentially. It also dampens the super charger whine.

My point is that without the cover in place and with a temporary closing off of air flow through the radiators more heat would be available around the charge coolers.However I do not think it would be enough given the fact the SC pump is pumping coolant at near ambient temperature thru the charge coolers.

If anyone has looked at the "finning matrix" inside a charge cooler you can easily imagine the icing up process.

Also that matrix gets quite clogged/coated with hard oily deposits at possibly as early as 60k miles. However that oily deposit would I think act as an insulator on those fins in the matrix.

That matrix, if iced up, would easily lead to the volume of water under consideration here.

There is also quite a thick "pad" of insulation under the SC on my car to help lower the heating effect of the engine on the SC.

 

They day before, I had a pair of 1000ft drives in close succession, with no time for the engine to heat up. Then I went to work, later I drove home. The weather conditions were a little more extreme on the Thursday, ~20F in the day but 2F when I got out of work. The day it froze it was colder all day. For those of you wondering, the engine cover is still in place and there are no modifications to the car.

One thought though, on Thursday the car spent most of the morning on a lift. I was having the snow tires fitted but a couple of the lug nuts snapped and it took a while to get them out. I wonder if being "warmed" like that, i.e. in a heated building, prevented it from freezing that night? Chances are it had no effect, but we can't be sure.

 

reading about the engine cover and that insulation pad under the blower reminded me of some information that may (or may not!) help. First, both our cars have the engine cover on. BUT, my wife's STR does not have the insulation pad under the blower. I took it out when I replaced the hose under the blower and never put it back in. BUT my SV8 has the pad in place. Also, when I had the blower off of the STR, I cleaned everything out to get rid of all the crap in the intercoolers, throttle body, intake elbow etc. BUT (another but!) my SV8 hasn't had this done yet so it is all original with all the oil and crap buildup over 288,000 kms. So in my possession are two identical engines, one clean and without the insulation pad and one all dirty and with the pad. Neither has frozen. Don't know if this helps but might be relevant.

 

Perhaps my reference to Boyle's Law back at post #21 needed deeper explanation. Any one interested on Gas Laws may find the following helpful - Gas Laws #1 and/or Gas Laws #2

If we accept that "icing" has occurred in the induction tract, then the later process of hydro-locking appears perhaps inevitable and evidenced by OP's findings . . . ice has melted . . . run down induction tract under influence of gravity . . . enters whichever cylinder(s) enabled by inclination of car/engine and open inlet valves . . . then re-freezes once engine's residual heat falls below freezing point. Whether this takes all night, end of shift at work, or just several hours would appear influenced by local atmospheric conditions.

I'll bet that, if the time interval between stopping and attempting re-start was short enough that re-freezing had not yet occurred, we would be blissfully unaware. So far, I am in complete agreement with Mikey's explanations . . . but, why is this "icing" in the induction tract occurring and why only (?) on SC, not NA, engines?

I suggest that these Gas Laws (induction air, with its water vapour, is precisely that) and examples of "icing" areas of vastly reduced pressure and temperature such as carb venturis and across aerofoils are not only relevant, but demonstrate what is happening here. Anyone who has manhandled settings on a brace of race engine Webers will attest to how cold those bell mouth suckers become . . . and under race conditions. Perhaps this link on aviation "icing" by the Science Guys will help.

Understanding the function of the intercooler is the key and its propensity to super-cool the air under certain conditions. Therefore, I suggest two possible solutions . . . (1) provide an "end of drive cycle" timer during which the induction tract, notably intercooler, is heated to melt ice and expel it before engine stops . . . or, (2) provide measures to prevent the intercooler ever dropping below freezing, as Mikey suggests.

I like JagV8's questions at post #20 and his focus on "why now? why not when cars were new?" . . . but . . . all such issues now seem scotched by OP who reports stock set-up. I also like Occam's razor . . . perhaps instead of "wear" in now older cars . . . a simpler explanation could be that while cars were newer, owners were less likely to venture out with their pride and joy into conditions where bits froze, broke or fell off. Gosh, you folks deserve medals for living in those conditions!

Cheers,

Ken

 

A couple more thoughts while putting tin foil on the windows on my house. Feel free to laugh at or ignore these ideas, as required.

With the PCV system, where are fumes drawn into the intake manifold? With a worn engine, this would leave an oily film that repels water. Not sure this would be upstream of the area where ice forms, though. Might partially explain why only some cars have the ice problem.

Is the EGR valve or plumbing anywhere near the ice prone area? Another longshot idea, but what if heat escaping from EGR system was planned to help keep ice from forming? Meanwhile, carbon builds up inside the passages, forming an insulating layer, letting less heat escape.

Okay, back to my tin foil....

 

So it may help leaving some crappy oil deposits in the under SC area!

 

Anxious for BenPearce to weigh-in with the results from his blue car. White was #5 and #6 saturated. If Blue likewise, we may have a clue as to the rarity, although it won't explain why our only reports are of cars with several years of service.

Just a thought, but if #5&6 are the only cyl's in the "drain path" then in addition to all the other discreet variables required to precipitate this issue, the engine must come to rest with the intake valves open in 5 or 6 or both (I'm assuming based on sequential firing order mentioned earlier that both are open during some amount of time but that one precedes the other in opening/closing) However, also as previously mentioned, the drain-path and low point may well be influenced by inclination of parking spot.

As to no reports when the cars were new...in addition to the postulate that people may not be inclined to take their new prize out into such inhuman conditions, consider that those still supported by the new car warranty would likely ring up their dealer (or arrange towing on their own to same) with simple instructions, "Car's dead. Fix it, call when it's ready" and who knows what actual diagnosis accompanied "the fix" as the car was returned? What I'm saying, is that it is probably the rare owner who is an enthusiast and also buys a NEW Jag, then experiences the corner-case conditions seemingly required, who then comes here to post about it.

 

The 'didn't happen when new' assumption is not quite accurate . I remember one of the reports from last winter, or possibly the winter before, made mention of a Jag dealer who was indeed familiar with the issue and had been seeing every winter for x number of years.

 

Good point. There may be more instances of this situation than we see reported. More than likely the case.

 

Most have been out of warranty for a long time now and quite a few have owners on here.

So far only the 4.2 SC fitted to STR & XJR, it seems.

 

That is true however what about when they were under warranty many years ago?

 

I think we have no data.

I don't recall any of the long-time jag techs ever mentioning it, though of course some work only in hot climate areas so would not have met it.

 

Another data point from X350. Just trying to establish some linkage throughout these threads as it is still a somewhat mysterious occurrence.
https://www.jaguarforums.com/forum/x...inders-174082/

 

Ok, it has been a while since my last update:

Good news, both cars run just fine. The blue car had ice buildup in cylinder #3 but I couldnt find any in any other cylinders. It wasn't nearly as much as I found in the white car, suggesting to me that drive time is definetly a key factor.

As to prelockup drive schedules:

White car, two days before it made the hour and a half trip twice, and the day before it did not move. So I dont think that had much to do with it. Weather was about the same as the day of lockup all week, which is really befuddling.

Blue car, two 30 minute drives each day for at least a week before in subzero weather. Two days before it made a 3 hour drive, the day before it made another 3 hour roundtrip, and the day-of it drove for 20 minutes to the lockup location. Again, very similair subzero weather each day. (Around -15 C as a low)

As to the charger cover theory, I dont think that is related. White car has it, blue car does not.

The EGR valve dumps exhaust gas into the elbow after the throttle valve but before the supercharger. It might be that the oil film makes it worse, I know the charger along with all intake parts had a thin film of oil on them.

I used a boroscope through a plug hole but didnt see anything interesting other than smashed up ice. The intake valve didnt seem to be blocked open by ice.

I have no idea as to why this has happened now as opposed to some time in the last two winters I have owned these cars. I thought the white car freezing was an extremely rare instance, until the blue car froze up. As to preventing this from happening again, when i get back from vacation I will to some temperature monitoring and measuring to find out roughly how long it would take the intercooler to warm up at an idle after a long drive. I would expect a few minutes on top of a 100 degree C engine should do it.

 

. . . suggesting engine stopped and then offered ice build-up a different drain path compared to white car . . . unlikely to give valid conclusions about quantities of cylinder ice, but suggests that same process is occurring in both cars.
Whether manually, or via timer, this end-of-run de-icing idle offers an immediate no-cost solution.

As to cause(s) . . . Perhaps you can rig a DVM with thermal sensor leads from intercooler body back into cabin. That live temp data, monitored against ambient temp and drive time, may prove very interesting . . . and, I predict that, somewhat like the wind chill factor on low temps, will prove startling! Reasons given across many of the posts suggest that the "simple" cause may have nothing to do with engine wear, age, oil or crud buildup . . . indeed, may not be a new phenomenon at all.

Cheers,

Ken

 

I believe this was tried on one of the other cars (non S-type) and didn't seem to work. The engine ended up hydrolocking anyway.

 

Maybe IAT2 would help? I'm not sure how easily you can get to it if you want to connect direct (electrically).

It's readable with IDS/SDD, which is hardly convenient.

Or via an elm327 but you're going to have to teach some software about how (torque pro should be able but won't support it unless taught) - let me know if you want to try.

 

I'm going to bring back an old thread just to keep all the data together. My '04 XJR has frozen again. This time after almost no driving. It's been very cold here all week, below 0F every night and single digits the rest of the time. I last drove the car on Sunday December 24. Since then we had Christmas and I've had the week off from work. On Monday we had 4" of snow and I moved the car very briefly to do the snow clearing. It was fine then but I didn't keep it running long enough to warm up. On Wednesday I went and started the car, because I know it doesn't like the cold. It took a little longer than usual to start, but it started and ran fine. I ran it for about a minute, satisfied that it wasn't frozen. Today, Friday, I went out to do an errand and the car wouldn't start. It cranked very slowly for a few seconds and then stopped. Now all it does is click, which is exactly what it did last winter when it was frozen.

Somehow I don't think that this is a condition that only effects cars that have been on long drives. It really seems like it can strike anytime the temperature gets around 0F.

 

I wondered who would be the first to report hydro locking this winter, Lucky you.

Ican't say Immediately agree with the freeze up process as there must be heat an moisture present to first freeze in the inter coolers, followed by a thaw and refreeze cycle of the moisture, you're missing almost all of the elements.

At this point you'll need to thaw the engine an pump the water out. The weather fore cast at least here does not seem to provide much opportunity for that in the next few days.

Let u know what happens.