The issue isn't with the temperature of the engine, as the needle is right where it's supposed to be. I thought about blocking the radiator cover, but that's not really the problem. It seems to be related to the temperature of the air.

I'm not going to chance it this winter, so the car is up for sale. Hopefully someone else will be interested in pursuing this.

 

Make me an offer!

 

SWMBO just gave me that 'don't you dare' look. There's already two more cars than parking spaces..............

 

True--but blocking the radiator airflow will increase the rest of the engine bay temperature and you won't be cooling intake air as much anymore.

Anyway, good luck with the sale! Seems like these cats are all tempermental in extreme temperatures. Mine has issues if it gets below 40F, the air pump switching valve starts popping and it also starts taking longer to fire while cranking

 

Blocking the rad will do little for increasing engine bay temps- and that's not the issue anyway.

If I've got the theory correct, airborne moisture accumulates as ice inside the air passages of the intercooler. After shutdown, the residual engine heat causes the ice to melt and the water trickles into the cylinders inducing hydraulic lock at next start up attempt.

If true, a work around would be reduce the effectiveness of the intercooler.

 

I thought I could make it all the way through this series of posts again before commenting, but alas I could not. There are a few points that people seem to be jumping to a conclusion over that might be worthy of revisiting.


I'm not bashing the above quoted post, but it does give me a place to start. Sorry if someone feels slighted.


As a baseline, I believe the subject at hand is that of hydro-locking on SC engines. Some amount - whatever amount that might be - is entering the intake system and finding its way into at least one cylinder. I have comments earlier in the thread where I was suspicious of my battery as a cause, but I am no longer of that opinion. The engine does not turn because it is internally blocked.


I also believe the problem, while most likely to occur in colder temps, is not so limited. I have experienced the problem on two occasions where ambient temperatures were well above freezing. I have also experienced the problem at temps below freezing, as low as zero F. I am convinced that the problem was water in one or more cylinders in all instances.


What was common in my experience were trips of very short duration, even once when I simply moved my car from the driveway into the heated garage so as to allow the accumulated ice to melt off exterior surfaces. I have never had the problem after extended drives, regardless of temperatures. I see that driving duration has been mentioned, but I challenge contributors to reassess their experiences to be sure.


Also, ever time it happened to me, the steam blown from the exhaust was extreme for several minutes.


I also believe that many issues we experience are symptoms of other underlying failures (cold driver's side heat = failed auxiliary pump = clogged heater core). Where longer duration drives are an issue in colder weather, I would look for a failed SC coolant pump as a contributor.


Anyway, what has been simply overlooked is how the water got there in the first place. It's either in the air or in the fuel. Oh, we've had lengthy discussion about compressors and condensation, but what about fuel, something that is complete unrelated to an air compressor's condensation capacity?


Say what? Are we willing to consider that the water is already in the fuel, captured by the added ethanol and methanol? Just a few years ago, the Fed determined that only +15% blended pumps need be labeled. And in our search for octane, we're actually buying almost exclusively blended fuels?


While the mentioned mixing is to achieve desired EPA ethanol consumption schedules, this stuff holds water like crazy and might really be the source of our increasing headaches.


So, I would offer that we should avoid blended fuels as much as possible which is even more difficult in winter when the winter mix is in distribution channels.


Also avoid ethanol/methanol additives as much as possible. While we might be tempted to pour in the occasional dry gas, resist the temptation unless it is absolutely necessary.


I was going to close by saying "Just my 2 cents" but I think you got more like 2 bucks worth.


Hope it all made sense.

 

The other day, when ambient temp was a little above freezing, I noticed quite a large puddle of fresh water under my 2005 XJR. I assumed that it was from the air conditioning however the puddle was larger than what I see in the Summer.
Could this be from the supercharger? If so it must drain down somehow and if some drain is blocked where would it go?
I normally do not take the Jag out is cold weather so this is the first time I have seen it. If this is from the supercharger then it can produce quite a volume of water under certain conditions.

 

I don't see why you are guessing that alcohol content is relevant.


It does not create water in the tank, it only enables water that is already present to mix in rather than stay as gobbets.


Since the fuel is composed of hydrocarbons, it is going to generate quite a lot of water as a product of combustion, regardless of alcohol content.

 

This has been a fascinating thread to read from England where the weather is usually not so cold, albeit damp.

When a multi-cylinder engine like a V8 is shut down, one or more inlet or exhaust valves will remain open. So there is nothing to stop water from somewhere in the inlet tract from flowing into the cylinders provided all or part of the inlet or exhaust tract lies above the valve array on each bank of cylinders. If cold weather causes icing in the inlet tract somewhere, and that icing lies above the valves, then when it melts it could flow down into the cylinders.

On the V8s, we can ignore the exhaust valve path as it is below the valves, however, the inlet valves are on the inside of the V, so the inlet manifold will lie above the valves, thus providing a path for water to flow. It is how that water gets there in the first place that needs investigation. If one can work out a path, then it will happen, on the old adage of "if it can happen, it will happen at some time and in some place, but we wont know in advance".

For instance, a Lancaster bomber in WW2 was once disliked by its pilot for its general sluggishness whilst flying. Quite by chance, whilst some flak damage was being attended to, it was found the ailerons were fixed on upside down. There was nothing to stop this happening at the factory other than delivery of the ailerons to the airframe fitters in the correct orientation on the trolley. If that somehow was wrong, the fitters just bolted the ailerons onto the aircraft as received. The aircraft did fly but not as well as it should have done to an experienced pilot.

 

Sorry but that makes little or no sense. Fuel is only present in the cylinders while the engine is operating. The volume of fuel per intake stroke would be difficult to collect and measure in even the most accurate laboratory equipment. That's why these cars get travel almost 30 miles while only consuming only 1 gallon of fuel.

If the fuel was contaminated with enough water that it cause any sort of problem as you've outlined, the engine wouldn't operate at all, never mind become hydrolock after shutdown.

Why would this supposed contamination issue only affect supercharged vehicles and not all cars?

As piglet pointed out, water vapour is a byproduct of combustion. That's what we see as exhaust vapour or dripping in cold weather.

 

The thread continues to focus on everything but possible sources for the water that is finding its way into the intake. Ever since Quintin Christy in 1942 identified that by adding methanol to the gas tank helped reduce fuel line icing by absorbing the trapped condensation, gas companies have played with various blends to solve the problem at the pump. Winter blends were the first move and with the ethanol blending of fuels, the problem is all but non-existant today.


My contention is that increased - and increasing - levels of ethanol (E) and methanol is, as a by product, increasing the water content in the fuel we purchase. We may be to the point where certain engines (e,g V-8 with supercharger and intercoolers positioned above the intake plenum) may be more sensitive to the increased H2O content.


It is my understanding that while traditional gas burn releases some H20, perfectly combusted E yields only H20 and C02. Add to that the water absorbed by the E, the more released/freed H20 will blow out the pipe.


Okay, so most of it goes out the pipe, but not all. Some amount is recirculated through EGR systems but I doubt this is enough to create the conditions we are seeing.


But combustion is not the only way to release the suspended H2O, simply compressing moist air - as happens in a compressor - will do the same. And since we're talking about SC cars only and the SC is a compressor, we might not so quickly dismiss the relationship between blended fuels and water anywhere downstream of the SC.


You don't have to agree, but when it first happens to you, you'll rethink your position.


Ethanol - Wikipedia, the free encyclopedia

 

I wouldn't agree no matter what. First- there's no methanol in any fuels. Essentially outlawed.

Since an engine is essentially a pump, please explain how any vaporized water in a cylinder would not be forced out the exhaust along with everything else. Don't forget that it takes a hundred CC's or so of water to hydrolock just one cylinder.

 

Also, the SC isn't on boost except at certain times - most unlikely to be just before turning the engine off. Almost impossible for SC boost to be relevant.

The TB is heated - well, is if working etc - might there be a path for water/ice somehow if not heated because of some fault? I don't see it but any chance?

If - and it does seem a big if - there really is this frozen engine stuff then it's so rare that it seems to me it would have to be caused by a fault on the specific car(s). Else why is it so rare? If it actually occurs.......

 

I'll take the one or two owner's word that it has indeed happened.

As to why it's so rare- the number of cars involved is a tiny fleet. Perhaps just XJRs and nothing else. As you've pointed out, this issue does not exist on S-type Rs.

Next is the combination of ambient conditions including an temperature of X and possibly a humidity of Y. This only happens on a small part of the planet and only a small fraction of the calender year.

Next is the operational cycle of the vehicle- perhaps long drives are required at high steady speed to allow build up of ice in the intercooler. Short trips and low speed/city driving would probably not permit the ice to form.

After the ice is formed, the car would need to be shut off and kept immobile for several hours for the ice to melt and trickle down into the cylinders. A long highway drive followed by city driving would probably allow the ice to melt gradually and pass through the engine, the driver being oblivious to the condition.

Just guessing.

 

Maybe. I don't know.

I see plums has suggested a damaged/stuck SC bypass. Another maybe, for all I know what exactly would happen. I'm not sure how anyone would test for it without a lot of hassle taking it apart.

 

Too much work for a casual, disinterested observer, such as myself, to sift through the triple-digit-posts and count others who've weighed-in with similar experiences, but as to thread-starters, it seems STR's are up 2-1 on XJR's:
https://www.jaguarforums.com/forum/s...5/#post1587493

 

Checking the SC bypass is not difficult to do.

Also my response to the other thread is:

Well the charge coolers will be circulating coolant at about the temperature of the SC radiator which will be close to ambiant air temperature not lower while the SC is not pushed.

The inlet mixture would be at about the same temperature as that on a NA car.
Am I wrong?

 

I've posted in the other thread. It all looks so unlikely... however, cars with actual water/ice in a cylinder need an explanation if it's not coolant.

 

Someone from NH has just had the same problem with their 2004 XJR.

I was worried about this issue last Winter and am now even more concerned.

I run my car without the engine charge cooler cover in place. I would think that if you were to temporarily block
air from moving through the radiators from the outside with the cover off the charge coolers that might help
avoid this problem?

The real answer would be a temperature controlled coolant valve set up that diverted some engine coolant thru the SC coolant system at a preset low ambient air temperature.

 

I leave my cover on, especially in winter - though we don't often have sub-zero (C) temps.