Before I get into my seized engine event, the previous time I flattened electrodes on a spark plug is when I ran way lean on a custom (i.e., me) turbocharged engine. The detonation in the cylinders was quite sudden and made me think that I had blown the engine. It turns out that it was just the spark plugs that needed regapping. BTW, a small paperclip is about 0.030" diameter and makes a great gapping gauge!

Today, I pressure washed my 2004 XJR and left it running for the two minutes it took. I then drove for an hour to my destination where it was about 3F or -16C. After 3.5h I get into the car to start it. The sun was shining today and the inside of the car was warm despite the outside air temperature -- perhaps this is a clue. The engine does half a crank and then suddenly stops dead. The starter was putting out heroic torque because I could feel the car move when it tried to crank the engine. *My feeling was that one of the cylinders was hydrolocked, but I couldn't make any sense of how this could be, so I gave up for the day and got a lift home.

Thanks to this thread I think I will go back (60 miles) to pull the plugs as see what is going on. Hopefully any water in the cyclinder(s) will not be frozen and I can let the engine "self-purge." BTW, I also recently developed weak drivers side heater output.

I can't understand how this could happen except for condensation inside the induction system. I have pressure washed my engine many times in the past, even in the winter and had no problems. This time, however, I barely even washed the front of the car, let alone under the hood, yet I got hydrolocking (I think). WTF.

Mike

 

Me too. This is a true WTF?

 

I don't think the washing is related, as the second time this happened to me, I hadn't washed the car for a few days or had it near any water. I suppose you could check the air filter to see if there is moisture in it, but mine was totally dry.

I'm planning to talk with a tech at a different dealer, and see if they've had any similar experiences with customer's cars. I'm having a hard time believing that this doesn't happen more often if in fact there is a design flaw in the system.

Looking forward to your results.

 

Did you fix the aux pump yet? After reading everything written in this thread I see that Mike :P having the same issue has the same symptoms with the same conditions. I wonder if it is just as some have theorized that under a given set of variables (temp, running conditions, bad aux pump) condensation is getting into your cylinders. If this the case then removing any variable changes the end result.

 

The water source causing the hydrolocking in one or more cylinders has got to be from ice buildup in the intake. Once parked, the heat from the block conducts into the intake manifold and melts the ice. The melted ice, also known as water, flows into the cylinder(s).

My head math tells me that there is not enough water in the air space between the intercoolers and cylinders, and so it must be ice buildup. It is not uncommon to have warm coolant heat throttle bodies and such to avoid icing. Could a failing secondary coolant pump be a contributing factor to the ice buildup?

Mike

 

My point is that as the mechanic stated this could make the problem worse. You both have/had poor drivers side heat and live in areas where it is currently getting quite cold. I'm a real big "math guy". If you figure how many XJR's there are out there, how many are in cold climates, how many failing aux pumps, how many are driven in the same fashion, and any number of other variables that maybe you both happen to meet. You get a very small number. It could explain why there have been few complaints. His mechanic said only a few in 5 years. That's a small number. Again, I hypothesize that if one of the variables is removed you get a different result.

I hope that both of you get your vehicles running without too much headache. Sorry to hear about you pain.

 

Your posts reminded me I'd seen a similar issue before. I thought this might help you guys; it's been going around in the TDI forums....intercoolers at freezing temps. These are diesels, so different animals, but similar symptoms.

"GraniteRooster's Frozen Charge Air Cooler (Intercooler) FAQ / Problem Summary

Problem
When driving in winter conditions (below ~20-25°F), external airflow over the air-air intercooler (IC) is cold enough to cause internal ice buildup in the IC and outlet charge hose assembly. Ice buildup may lead to a variety of operational difficulties including restricted intake, reduced power, LIMP mode, engine stumbling, melt water or ice ingestion, and catastrophic engine damage.

Occurrence
Ice buildup occurs while driving in cold winter conditions, typically below ~20-25°F. Melt water and ice ingestion may be experienced on subsequent engine start if the car is allowed to thaw while parked (such as in a warm garage, or warm parking lot above freezing temperatures).

Causes
This is a thermodynamic phenomenon caused by condensation and subsequent freezing or direct vapor deposition of water vapor as the turbo-compressed charge air is cooled through the IC and outlet charge hose assembly. Two main aspects of engine design contribute to the problem:
Low-pressure EGR is used to control NOx formation for emissions compliance, however, this recirculates water vapor rich exhaust back to the turbo and IC.
The IC design on these vehicles is very efficient, providing good heat transfer and economy (and good ice formation under proper conditions)

Symptoms
Ice
Restricted Intake & Reduced Power
LIMP Mode (flashing MIL’s, “Service Now” message)
Engine will not turn over (complete ice obstruction of intake)
Catastrophic engine damage (ice chip ingestion)
Water
Engine will not turn over, "dead battery" starter action (due to hydraulic resistance in cylinder)
Starter/electrical fires (due to starter overheating during attempts to start locked engine)
Engine will turn over slow / not start (drowning)
Engine will misfire, stumble, and run roughly upon starting (water ingestion)
Engine will misfire, stumble and run roughly upon acceleration (water ingestion)
Catastrophic engine damage (water ingestion – hydrolock)"

I cut that down a bit for easier reading.

Thread is here:
http://forums.tdiclub.com/showthread.php?t=302863

almost 300 pages of posts, so as he says, get a cup of coffee or tea. (yes, the TDI world is a little bigger than Jaguar)...but you can read the front and last few pages of posts to get some ideas.

Main cause seems to be the EGR recirculating warm moist air into the IC then it freezes causing all sorts of issues.

VW had to come up with a new IC kit to deal with it; some people still have issues, and often not covered if out of warranty (to the tune of $1,100).

 

Here's another synopsis of the issue:

VWVortex.com - TDI Intercooler Issue/Design Flaw

 

I'm with installglass...there seems to be a connection between the cooling pump failure and what is going on. It may not help to fix it, but it sure seems to be a coincidence. All the evidence points to icing/condensation, so heat can only help.

Quick cat, I am glad to hear the engine is running well. You are very lucky. It does not take much to **** the piston and crack an aluminum block...so we really need to figure this out and prevent it from happening again!

Also, the number of supercharged XJ8's sold is actually a fairly small number, compared to say, Fords, Toyotas, etc. There is a very good possibility that this is a design flaw with all the supercharged XJ8's, but the cold we have seen this year just doesn't happen often enough to highlight the problem. A letter to Jag may get some notice...

 

The Volkswagen TDI issue is similar to that seen on the Ford but not all that similar to Jag. The scenario of being parked in a warm garage after shut down is the opposite of QuikCat's case. This would cause ice in the IC to melt and be sucked into the combustion chamber during the next start.

The OP has only seen his problem when the car has sat in subfreezing temps, meaning that water in the IC would become ice.

 

Not to start a new hair-splitter, but the temps seen by both owners in this thread are quite common up here as they would also be in Nothern Europe and Scandinavia. In the many years these cars have been around, it still seems strange that there's something new to see.

 

I would agree, but the warm garage was just one theory...it seems to have happened many places, check out this map on where VW owners have had the issue:
https://maps.google.com/maps/ms?msid...c=A&dg=feature

I've not read all the pages, I just noted that there seemed to be two theories, that water leaked into the intake/got sucked in, or it has condensed via the IC/SC. I may be wrong in that.
If it's the 2nd case, then I think it could be a similar scenario; in the right conditions.

Maybe the EGR is also the culprit?

 

TDI - diesel - aren't these Turbos? So, it's exhaust that's being recycled and exhaust is full of H2O because you burn hydrocarbons
HxCy + O2 -> H2O + CO2 ... (not balancing x, y, etc)

But the SC engines are putting outside (fairly or very dry) air, heated by the charger, through the IC. Very very different.

 

Yes, I did fix the pump, 3 days prior to the second occurence. That was another reason I thought I'd be okay.
My drivers side heat was warmer than the passenger side. The new pump did make the floor heat hot on both sides (the vents are driver warm, pass cool, but that's for a different thread).

I called the Jag dealer in Minnesota with the thought that a cold climate dealer (no dealers in North Dakota), may have seen this situation before, and hit pay dirt. Speaking with John, the head service mgr, he knew exactly what I was talking about. They've had a handful of customers who have experienced the problem. The situation only presents itself in very cold temperatures. What they found is that the rotors frost up, and after the engine is shut down, the warm temps from the engine melts the frost, and the water drips down into the cylinders, typically in the rear half of the engine. Depending on where the piston is in the rotation determines if the engine will hydrolock. He thinks the water melting happens often, but the valve has to be open for the water to drain in, and the piston has to be on it's compression stroke in order for the water to not self-purge. Unfortunately, they have not been able to come up with a fix. They've talked JCNA and have made them aware of the issue but have not received a solution. His suggestion was to either let the engine idle for about 30 minutes before shutting it off, or to restart the engine about 20 minutes after it was shut off, thinking the frost on the rotors would have softened up by then, but not turned into water.

 

Ok, I'll buy that. Simple answer to me would be a turbo timer. It allows the vehicle to run for a specified time period then shuts it off. Can be switched off during normal temps but give you a period of idle time when you walk away. Unfortunately another expense but way better than hydro locking your engine and bending or cracking a valve/head/piston/block.

*Spitballing a simple effective solution*

 

Interesting info JagCat - good call on finding a dealer with a cold area! Interesting. Apparently it's going to be an issue with cold weather and all the forced induction cars coming out these days. I expect we'll be seeing more of these types of problems.

 

My brain is really hurting now.

The supercharger compresses air which causes it to also increase in temperature. How can ice form? We've debated whether moisture in the compressed air will condense and collect in the intercooler, but now the technician is saying that melting ice will drop directly from the supercharger housing into the cylinders. Is actually no IC on these cars?

I don't see how letting the engine sit at idle for half an hour will cause the ice to melt and go away vs. accumulating even more, or why restarting the engine 20 minutes later would avoid a hydrolock.

 

Just to racap, the ice in the intercooler and manifold melted, and flooded one or more cylinders causing the engine to refuse to turn over.

The short story is that simply pulling the second and third row plugs and turning the engine over will fix the hydrolocking problem. Water is unlikely to flow into the front and back cylinders. If the water in the cylinders is frozen, then you are going to have some fun. I used lots of methanol and paper towels to flush and dislodge the ice. After cranking the engine to purge the methanol and water, I replaced the plugs and voila: good as new... once the ice inside the intake finished rattling around and melted.

The long version of what happened:
The next day (today) I returned to the car which had now been sitting outside for 24h at around 0F. I removed the plugs from the cylinders third from the front, and found water frozen to the electrodes. The two cylinders second from the front had even more ice. I pulled all the plugs but didn't see any ice on the front and back cylinders. I poured a cap full of methanol ("methyl hydrate" or "methyl alcohol" down the plug hole. The engine still wouldn't crank. After several tries the engine half-cranked then seized again. I noticed a methanol and ice slushy overflowing the plug well. I soaked up the slush, and poured methanol down the hole. Repeat. Finally the engine turned over freely, spitting the ice and methanol out. One of my plugs had a skewed electrode, no doubt because ice banged it about at some point this winter.

After putting everything back together and starting the car, an off-beat rattle could be heard above the engine. It was ice, probably above the valves or maybe in the cylinders. It was not the hydraulic lifters pumping up--I know what those sound like. After a minute it went away completely.

My opinion on how to prevent this: after a long, cold-weather drive, idle the engine for a couple of minutes or until some heat can conduct into the intake system. This should melt any ice and burn it off in the cylinders so that it does not accumulate and hydrolock the engine.

Mike

 

I've been contemplating how this could work/happen and I think I've wrapped my head around it. A glass of ice water on a hot day will condense water on the outside of the glass. The cold internal temp of the glass causes condensation on the outside. Now we reverse this. The air being compressed in the supercharger is warmer and the housing of the supercharger or intake manifold is being kept cold from the extremely low temps outside. Causing condensation inside. This condensation then is able to reach the cylinders after shutdown. Allowing it to run for 5/10/20 minutes will allow the air temps to equalize as the supercharger won't be compressing at idle and remove any already produced condensation harmlessly through the engine.

Maybe I'm way off base but it's the best I can do to explain these very strange phenomena.

 

Yep...that's basically the conclusion I reached on page one. The latest revelation is that it appears to not be that rare of an occurrence.

Hey Quickcat, did you rev before shutting down for the last time it happened?

Ice and water in the cylinders is really living on the edge. So far it sounds like everyone is getting off easy with only bent plug electrodes. But I assure you that it will eventually do irrecoverable damage to the engine. If ice catches the edge of the piston, it has a lot of leverage to split an aluminum cylinder, bend valves or even rods.

I would not drive my car in deep freezing temps unless I had a garage to end up in. It's just not worth the risk to me!