I have an 03 s type r and I've had it for a little over 2 years now. Currently has 130000 miles with full synthetic oil changes every 3000 ish miles. (Parts master oil).

I've been having the restricted performance problem every once in awhile ever since I got the car. I've read quite a few threads on restricted performance but they don't seem to have the same details as mine so I thought I'd post another.

The only time it happens is when I first start the car if never happens while I'm driving for example heavy acceleration like I've read under other people's cases. It also has never just all of a sudden gone away like I have also read under other cases.

I have noticed that once the car warms up I can turn it off then on again and most of the time it goes away. Altho I would love to figure out what causes it and fix it I am most confused on why it occurs.

This is my second supercharged vehicle and on my first one the "knock alert" would come on and the supercharger would be bypassed so it just acted like a naturally aspirated engine. Obviously this made quite a performance decrease.
When my jag goes to restricted performance it feels very similar and very low on power. The blown 4.2 makes 400 hp at 9:1 compression and the 4.2 na has 300 hp at 11:1 compression I imagine a r with the charger bypassed wouldn't have much more than say 250 which is what it feels like when on restricted.

Please share thoughts on this.

If it is a knock sensor type of thing the engine has to be running to sense this but I have also noticed that once the car starts is restricted performance thing and I go to turn the car off then on that instead of actually starting the car I just put it in the "run" position it still says restricted.

If the rs (restricted performance) is a engine running problem it shouldn't be able to be noticed until the engine is running. Please also share thoughts on this. I also notice the exhaust smells really bad when on rs but not bad cat sulfer type of smell.

I did read that there should be engine codes while on rs that I will check next time. Since the USA no check engine light while on rs I've never thought about checking them.

Additional info. ... I've replaced 2 coils. One around a year ago that completely stopped working and one a few weeks ago that was only malfunctioning while under heavy acceleration. I also replaced the important o2 sensor. I think upstream (Grey connector) . Altho the rs frequency hasn't changed.

My apologies for the long post

 

I accidentally posted this twice and would like this one removed. Help on how would be nice =)

 

Damn phone, mods please delete.

 

What are the code(s)? Can't really help without.

 

Either my tool doesn't read them or they are gone already. All my tool says is p1111 which it displays as system clear. I'll try to get my friends computer link and see if I can find anything else

 

Don't assume anything. Except that it's likely the battery.

Also, get an OBD tool (see General Tech forum). They're much cheaper than the oil you're changing so often that I gasped. You really don't need to do that. Think of the extra wear caused every time you start the engine after a change.

 

Kert-

As few thoughts.

As Jag V8 has said 3K mile oil changes, especially with synthetic oil, is an absolute waste of money. The factory interval with dino oil is 10 K miles. This obviously has no bearing on your problem.

Also- there is no bypass for a supercharger. It is a mechanically driven device with no clutch mechanism to engage/release or other devices to relieve excess pressure, very unlike a turbocharger. The restricted performance feature of the car has no effect on the supercharger.

Again as JagV8 has suggested, the battery could be the culprit. These cars do weird things as they start to go.

 

It's gonna be the battery....

 

Kert, your problem sounds like one I had some time ago.
Have a look here: https://www.jaguarforums.com/forum/s...nt-pump-81392/

Sounds as though the s/c auxiliary coolant pump has gone. If so, the car drives OK until you put your foot down - then, within a few seconds, the supercharger overheats and cuts out, you get restricted performance and reduced power. Let everything cool down, and all seems well again until next time... And a definite sensation of only about 250 HP.

Don't confuse the s/c aux coolant pump with the regular aux coolant pump. The s/c pump is only fitted to the "R".

 

Jagv8... I have a innova 3150b that has worked pretty well so far even with the jag specific codes. It said rs yesterday morning and I restated it once warmed up and it went away then didn't check codes till last night so maybe it was cleared already. I'm still planning on getting a obd2 usb to hook up to my laptop because more info seems to be available with that. Also. .. Other than break in periods for the Rings to seat I've never heard of used oil being better than new. I mentioned I use parts master oil because it's Baxter auto parts in house brand and barely over 5 bucks a quart where everything else is around 7 minimum. Being the cheapest oil available I figure is probably not as good as others. You get what you pay for right. My last oil change, oil and filter, only cost me 55 dollars. Reguardless I will probably wait closer to 5000 now knowing that jag says 10000 and I did some research and found 7500 is also very common for jags. If the reason for oil is to lubricate the engine I am stumped as to why waiting longer is better. It would seem that the longer you wait would provide more debris in the oil (blow by ash and gas from cyliders and metal flakes from crank/cam/piston wear) all of which would seem bad for engine lubrication and wear. I am very interested in the reasoning behind the longer oil change intervals. Also please understand that I mean no disrespect I am just curious. You also mentioned is most likely the battery which I have seen that being the solution a lot and with all the electronics in these cars not surprising at all. I am curious tho on if there is a way to verify this without replacing the battery. Will it simply have low voltage or can a load tester be used or is replacement the only verification?
Mikey... I have a grand cherokee with an aftermarket kenne bell charger on it and it has a bypass valve on the side of the charger that just re circulates the compressed air back into the intake elbow before the supercharger so when a knock is sensed it has a way to relieve the engine of the engine destroying boost. I thought the jag might have a similar system under the sc or something because the lack of power while on rs on the jag feels almost identical to my jeeps sc being bypassed. It was just a thought. I could provide a picture of the jeeps sc bypass if interested.
Robinb... I read the linked thread and it was very informational, thank you. I checked the fuse and is fine but I don't think it's the sc coolant pump. The car has never switch to rs while driving. It only shows rs when I start the car and it seems to say rs before I even start the car is already there when it gets to the run position (probably another sign that it is the battery and some component isn't getting enough voltage upon power up) also the car has plenty of power when flooring at all times even enough to spin my 285/40s a lot of the time. I have however noticed the inner coolers being quite warm to the touch. I have a laser temp device tho and will find the actual temp of the inner coolers next time I drive it. Does anyone have any figures on what the temp of the inner coolers should be? Obviously a range. .. I will further investigate the pump in any case. Any tips on location of this pump?

Thank you every one on the help so far

 

If you are doing your own work get the shop manual. The JTIS. It's free on this site. It shows where all that stuff is.
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3K mile oil changes were appropriate for '50's vintage engines and '50s vintage oils. Technology has changed dramatically so that virtually all cars today have 10-15K mile oil change intervals.

You can change the oil at 3K miles or 3 times a day if it makes you happy, your car couldn't care less.


You will need a specialized load tester for the battery- straight voltage means nothing.

 

The Innova is probably OK if it reads codes etc.

Make sure you see P1111 or P1000 else tell us and probably your Innova actually is no good here.

Every time you change oil you run the engine with new oil that is temporarily absent from all the places you drained, doing damage. There really is no reason to do that as often as 3K or 5K but it's your choice.

 

I always get a 1000 or 1111 code. Rs again yesterday with a 1254 code saying throttle valve spring limp home malfunction

 

I suppose it might be this?