It’s a 2002. Even the best mechanics make mistakes (I hear) so of course it’s possible he was wrong, or maybe somebody did something earlier (during normal maintenance?) that could have caused this. And this guy has the top Jag shop in this part of the country – not that there are many competitors for that honour. Other than the dealer, his is the only shop that specializes in Jags.
Intuitively, I agree that it’s unreasonable to think all the injectors would fail at the same time, unless there’s some component that controls them all (this harness people talk about?) which is failing, at least intermittently.
The only issues this car has had have to do w/ electronics (quelle surprise – it’s a Jaguar) and the front suspension. I have on occasion noticed that the car ran rough when it’s cold – chugging a little – but only for maybe half a minute until it warms up. On one prior occasion the car wouldn’t start; that time, I had it towed to the shop but it started fine for them & they found no indication of a problem. I suspect that problem was somehow related to this, but have nothing but a gut feeling founded on ignorance to back it up.
It has 125,000 miles on it now; I’ve started looking around for something to take its place, but can find nothing that has the required attributes. Even the new Jag convertibles are on the ugly side. The Italian cars are unattractive and cramped. All the German convertibles have no trunk-room at all when the top’s down; the new Nissan roadster has a horribly rough ride. The Lexus and Toyota convertibles look, to me, overinflated; I could go on, but the upshot is the best option I’ve been able to think of is a newer-model Jag XK-8 with low mileage that will, I hope, last long enough for some manufacturer somewhere to come out with a luxury-touring convertible that suits. Maybe Chrysler will build a convertible model of the Dodge Challenger that will, miraculously, and against all experience, turn out to be a reasonably reliable car.
I’m sure when he said “no compression” he wasn’t speaking literally.
Would the gasoline remain in the oil for any length of time? It’s been a while since this happened (though the oil hasn’t been changed since then – I was planning to do that in May, before my next road trip).
IC engines are not that totally dependent on oil for compression. Engines will still START with very low compression. Even at cranking speed, there is always enough compression to start an engine. There is no liquid gasoline sloshing around inside engine cylinders in modern fuel-injected cars…The gasoline evaporates instantly unless it’s 30 or 40 below zero…
The Jag may have not started, but lack of compression was not the cause and squirting oil in the cylinders was not the cure…This is one of those Fantasy Island threads…
As I recall – it’s been a while, so I might misremember – it didn’t sputter or cough, it just cranked. I don’t recall it ever sputtering or coughing, though there have been occasions, when it was cold, that it chugged a little upon starting.
On a couple of occasions the dashboard message lit up with a “restricted performance” message, but both times that happened (and they were two widely-separated occasions, like a year apart, and probably irrelevant to the current question) I had the shop plug the car in to the diagnostic machine and they found no codes that would explain the cause.
Well, obviously I don’t know enough about how engines work to have a real opinion on any of this, but I’ve had several people tell me – the mechanic, members of my car club, and writers on this and other forums – that ?Too much fuel will wash down the oil off the cylinder walls and drop compression.? I know what compression is in the abstract sense, but in the context of an internal combustion engine, I don’t really know what compression has to do with anything, beyond the vague notion that, in order to have a spark ignite the gasoline, you have to contain the gasoline in an enclosed area so it doesn’t drift away like an inattentive pet.
Still, the mechanic I go to is very well-respected in this area, and the only complaint I’ve ever heard about him is about how much he charges. I won’t easily set his opinion aside as you do. The car would not start; he found no (or low) compression; he put oil in it in some fashion, which “got the compression up to [some magic number of PSI, I forget what].” The car started, and continues to start and run with no discernible problem. It may be post hoc ergo propter hoc, but I don’t see any suggestion of an alternative reasoning.
And you can count me in as also being one that on more that one occasion has seen the cause of a no-start condition to be total loss of compression caused by fuel washing down the clylinders and all that was required to remedy the situation was that these same cylinders be “oiled-up” through the sparkplug hole. Once oiled up and a removal of the condition that caused the wash out the car needed no further attention.
The only thing I can think of is if there some kind of electrical anomaly which was causing the engine to possibly not receive an ignition spark or something of that nature and an extended spell of cranking with no spark simply allowed too much fuel to pass into the engine without it being ignited.
To start and run the engine needs sufficient pressure in the cylinders. This is created when the air/fuel mix is compressed by the pistons on their way up in the cylinders. Think of it as similar to pressure in the tires, just a lot higher.
Normal compression pressures would be in the 185 PSI range, give or take. If the pressures drop too low (say down in the 100 range) due to gasoline washing the cylinder walls then it’s quite possible for an engine to refuse to run.
Example, just to illustrate. A dealer I worked for hired a general lot man and one of his duties was to start every used car on cold mornings just to make sure there were no problems. This guy was an idiot to be blunt about it and carried several cans of starting fluid (ether) at all times. On several occasions we had several cars brought to the service dept because they would not start.
The first time this happened kind of threw us because the boss said it was running like new the day before and we had no idea what was going on with the ether. Ignition spark, fuel was provided, engine low miles, etc. but would not even spit.
After removing a spark plug I could smell ether. This led to removing all plugs and performing a compression test which showed readings of 60 to 90 PSI. All way too low of course.
I gave each cylinder a squirt of oil, reinstalled the plugs, and voila. It started right up, smoked a bit from the oil, and was fine forever after.
That’s just an illustration of what could possibly have happened here although in this case the problem was man made and in your case it’s close to impossible to ever determine what caused it.
Does this engine have a fuel pressure regulator with a vacuum line?
Check for the presence of gas in that line.
A leaky diaphragm in the regulator could let extra fuel into the engine.
If you haven’t already changed the oil pull the dipstick and check for the smell of raw gas.
I would switch to motor oil one grade heavier (ex. 10W-40 instead of 5W-30) for highway cruising in warm weather.
I don’t know about the fuel pressure regulator, but I’ll ask my mechanic about it, and will smell the dipstick (hard to keep a straight face when I type that) when I get it out of the garage. I was going to change the oil pretty soon anyway, but will check for that before I do.
I used to change the oil every 3k miles, but then I read the owner’s manual so now change it every 10k.
Are you recommending changing the grade because of this problem, or because of the weather? Last oil change, I noticed the mechanic put in 20/50W oil, which means next to nothing to me, except that I think it’s unusual. (When I was young and did my own oil changes, back when you could dump the used oil behind your garage, I know I always used 10W30, but no matter how often the numbers are explained to me I never remember which oil to use when.)
Going 10k miles between oil changes is not good for the engine at all.
I’m a bit puzzled about the use of 20/50 engine oil. There’s nothing wrong with that particular weight but generally that kind of oil is used on high mileage engines during summertime and usually if there is not much stop and go driving involved: most of it being on the highway of course.
If you live in Arizona then fine. If you live in a much cooler, or cold, northern area then this kind of oil is like thick syrup when cold. And in March to boot? Weird choice for this time of year.
If all you do is cruise the highways I suggest you change the oil every 5000-7500 miles.
Basically the higher the numbers the thicker the oil. Plus oil naturally gets thinner when it gets hot.
Cruising on the highway tends to make the oil hotter, so a thicker oil might resist getting washed off the cylinders.
Oil can also get thinner with mileage as it wears out. How many miles were on the oil when it broke down?
Soooo, it was your VW motor I had to swerve around, while driving my VW without working brakes.
I believe Old Schools explanation is the only one that makes sense.Pouring oil in the cylinders will mess up the oxygen sensors and catalytic converter.Either your “mechanic” is clueless or 80 years old.I wouldn’t advise doing this again.
I think you might possibly have other issues or the higher ethanol content is not good for your vehicle.
I live in South Texas, where winter is usually on a Thursday in February. Substantially all of my driving in this car is on highways (not, usually, freeways), and I only leave home when the rest of the country thaws out. If it’s not warm enough to drive with the top down, the car awaits my pleasure in its garage. So it sounds like this 20/50 oil my guy put in is a good oil for me.
I wouldn’t use 20w50 oil unless the manual specifically recommends it. Thicker is not always better. Some vehicles today use 5W20 with no ill effects, and are designed for it.
Let’s assume that what your mechanic says is true. In that case, wouldn’t some cranking until the engine built up oil pressure restore enough oil to the cylinders to restore compression?
That’s what happened when I had a slightly leaky injector. The engine ran rough, until the gas that dribbled into the cylinder when the car was off burned off.
