Is your mechanic a Jaguar certified tech or an independent? Was he the guy at the dealership?
Who did your tune?

 

This is a far better plan than participating in screaming matches at the dealership, assuming that this bridge has not also been burned.

My SWMBO (who I guess should rightfully now be called 'Grandma') was the OEM head office warranty person who would handle calls from shops regarding complex cases. I (Grandpa) was the OEM tech guy who would do the investigative work and render an opinion as to whether Grandma should get out the 'ole chequebook. Or not.

It's amazing how much difference having a dealer go to bat for the customer can make.

On the other hand, relying on the opinion of 'some random guy' who makes unsubstantiated claims about known defects and recommends 3K oil changes as a solution usually damages the owner's credibility even further. One sided ranting on a public discussion board doesn't help the case either.

 

The 5.0L engines in the XKR have had "oil starvation" issues resulting in "blown engines" many times. (There is a thread as I recall that graphically showed the damage done in a series of photos taken by the owner.) I wouldn't call it common, but more than occasional. When I purchased my XKR, it had an engine that had to be replaced due to the same issue. But I guess you could call me grandpa as well, so what, that just means I've got more experience and wisdom accumulated than you.

 

The oil pressure in most modern vehicles isn't going to increase proportionally to RPMs. Obviously at idle RPM you won't have as much, but virtually as soon as the engine is moving, the oil pump will produce more than adequate pressure. The pressure is relieved very low in the RPM range and subsequently bled off. So I don't think it is accurate at all to suggest that there are flats spots built into the ECU calibration to protect the engine from low oil pressure, or that the transmission shifts to prevent load versus oil pressure.

Pressure is only critical in so far as it relates to flow. Oil flow or lack of it is probably more common as an issue in bearing failure than pressure, notwithstanding stuff like hydrodynamic journal bearings. Particularly in modern engines that are designed to run synthetics, super-high pressure is not required as much as is flow.

Flat spots are typically as a result of timing pulls which are designed to help pass emissions cycle testing at particular load vs. rpm points.

FWIW, oil consumption and subsequent main bearing failure due to starvation has been an known failure item since 2009.

 

Just curious how much does an engine repair like that cost ?? And why do you say your tune was bad ?

 

I'm an engineer at work and a mechanic at home. Like I said, a design issue would affect every engine, as far as i know , your issue is unique.

 

it actually says in my vehicle handbook not to overload the engine at low RPM 'as reduced oil flow at low RPM can cause irreparable damage'. As for the term pressure, that just being picky, flow / pressure etc., all affected by engine RPM to a certain extent. Yes once you reach a certain RPM, pressure is limited by the pressure regulator within the pump, but that is why the manufacturers warning is there. As for in built flat spots, they ARE built in for engine protection, low oil flow/pressure is one reason, and also to protect the engine from certain resonant vibrations that can occur in distinct RPM bands under certain loads, yes emissions is another reason, but all together are a good enough reason NOT to mess with stock settings

 

'FWIW, oil consumption and subsequent main bearing failure due to starvation has been an known failure item since 2009.'

my question then would be why are you promoting tuning products for a car with know oil starvation issues? surely you wouldn't go any where near them???

 

the known oil starvation problems are raised by low oil level of the engine due to high oil consumption as written
by Stuart , not by faulty design or failure of any engine component.
In such case you have to blame the driver who doesn't care about the correct oil level .
Next you can blame jaguar for using an electronic dipstick which only works during user interaction.
No user action no warning . Leaving out an oil pressure sensor doesn't helps either.
To narrow down the problem it would be helpful to know how many oil was drained after the breakdown.
Regards
Ulrich

 

Stupid question. Lets not go attacking a sponsor because you disagree with him...

Now that's not entirely fair. There are many other instances that could cause oil starvation including part or design failure. The oil pan could be a poor design if it allows for oil to slosh away from the pickup during high G corning; this has been the case with numerous cars and really every engine is susceptible to some point unless it has a dry sump system. However, some designs are much better than others and usually not a problem. I imagine high G cornering was not the issue here.

 

'Stupid question. Lets not go attacking a sponsor because you disagree with him...'

sorry? why is it a stupid question to ask if someone who openly promotes performance tuning F types why they would do so if there is a well known and documented issue of oil starvation on that engine? i think its a perfectly fair and reasonable question

 

I have always enjoyed a great relationship with my Jaguar Dealer from purchase to after warranty service. I have also listen to their advice about making any changes without any regrets. Sorry to hear about your big $$$$ issue.

 

My dealer just recommended changing the oil every six months. Should I disregard them as some random certified Jaguar repair shop or is there a problem that they are seeing. I'm not trying to be disrespectful.

 

That would entirely depend on why they recommended this - what reason did they give to you?

 

And ask the dealer why the OEM says one year. Quite a contradiction. Is it 6 months irrespective of miles?

 

They said 6 months or 7500 miles. The reason given was for your high performance car it needs to be done more often.

 

How would this help with the supposed oil starvation problem? (It wouldn't)

BTW- almost all dealers irrespective of marque love to recommend shorter oil change intervals. Lots of profit at $200 a pop.

 

A tune has no impact on oil starvation, it's not going to make anything worse or increase the chance of engine failure. Why would a company avoid business because of a completely unrelated problem? Especially when that problem is so infrequent... its the tuners job to safely increase performance, not worry about factory issues. They aren't selling you a fix here...

There's no scientific basis to this, so I would ignore it. Sounds like they are just hoping for the extra business. Remember, oil doesn't wear out... it only gets contaminated or runs out of helpful additives. Changing it before either of those things happen is just a waste.

 

I've seen reports on other forums with engines that use the paper oil filter element (rather than canister) like ours where incorrect installation of the element causes twisting/collapse of the filter impacting the oil flow and in some cases leading to oil starvation and failure of some kind.

http://www.peachparts.com/shopforum/...s-p1120585.jpg

Did somebody say our cars really don't have an oil pressure sensor ?

 

i think you really are missing the point here. in a car has know oil issues, then adding a tune to that car is going to increase the chances of engine failure. I never said that a tune would cause oil starvation, but in an engine that is supposedly prone to it, only an idiot would condone a performance tune on it. surely you can understand that logic????