Jaguar X300 Parts interchangeability

Jaguar X300 Parts interchangeability

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Alster370

Original Poster:

10 posts

84 months

Saturday 18th March 2017
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Been viewing jag threads for months but first time poster. Got a budget of £4k or so to get a jag this summer, narrowed it down to 4 options.

X300 4.0 Sovereign
X300 XJR
X308 4.0 Sovereign
Daimler Super V8 (would need to find another 3k at least)

If you cant tell by that list, im looking for a fast jag with the best ride possible and most of the toys, don't need it for high speed cornering, just wafting about. My problems with the X300 XJR is that I don't like the sport interior (which is always in black, yuck!) so If I did go that route I would look to swap the interior for a beige one from a sovereign or a daimler. The second issue is the ride, which I wouldn't enjoy, so im wondering if parts like the dampers and the springs are interchangeable across the X300 models, so I can fit an XJR with touring dampers, springs and obviously 16" alloys, allowing me the power of the SC AJ16 but with the comfort of the sovereign?

Another mini question, asked a jag trader about the difference in refinement between the x300 and the x308, and he said that the soundproofing is improved on the v8 and therefore the x308 is the quieter car. Just wondering If you guys agree with that, and if so to what extent is it quieter?


a8hex

5,829 posts

222 months

Saturday 18th March 2017
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Alster370 said:
My problems with the X300 XJR is that I don't like the sport interior (which is always in black, yuck!)
While the wood work and carpets are black the rest of the sports interior doesn't need to be. I'm pretty sure the same choices were available on the X300 XJR as they were on the X300 Sport. My Sport has the ivory leather so a lot of the interior is light.
If you want ride comfort then for the X300s there were 3 levels. When I tried them back when they were new I found the XJR was rather firmer than I wanted to live with. The Sovereign was softer than I wanted. The Sport's suspension was, for me, the goldilocks level.
They made 4L versions of the Sport, so you might want to add that to your list.
The Daimler Super8 if you can stretch to one might be the ultimate wafter, but what about V12?
Remember, the only reason for only putting 4 cylinders in a row is that you can't afford to do it properly and put 6 there.

Alster370

Original Poster:

10 posts

84 months

Sunday 19th March 2017
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a8hex said:
While the wood work and carpets are black the rest of the sports interior doesn't need to be. I'm pretty sure the same choices were available on the X300 XJR as they were on the X300 Sport. My Sport has the ivory leather so a lot of the interior is light.
As far as I know you can get a sport/XJR with walnut/oatmeal interior, but its rare to get a sport/XJR that doesn't have ivory with black wood, ive only seen one, might go test drive it actually.
http://www.autotrader.co.uk/classified/advert/201701211536837?price-to=5000&sort=price-desc&make=JAGUAR&radius=1500&advertising-location=at_cars&postcode=s188xy&model=XJ&onesearchad=Used&onesearchad=Nearly%20New&onesearchad=New&page=1

a8hex said:
If you want ride comfort then for the X300s there were 3 levels. When I tried them back when they were new I found the XJR was rather firmer than I wanted to live with. The Sovereign was softer than I wanted. The Sport's suspension was, for me, the Goldilocks level. They made 4L versions of the Sport, so you might want to add that to your list.
The last Jag I drove was a 4.0 sport, was nice and comfortable and handled bumps pretty well, but was one in need of TLC so Im not going to judge all sports on that example alone. My main objections to the sport are the lack of toys + the normally black & ivory combo, I prefer the seats in the sovereign too.

a8hex said:
The Daimler Super8 if you can stretch to one might be the ultimate wafter, but what about V12?
I dont think my wallet could stretch to that for daily fuel. Il be doing 120 miles a week so the 4L I6/V8 should average 20mpg, which is fine by me. I also know alot less about the V12 and while it may be smoother than both it is quite power deficient for its size and weight.

Im looking to buy from mid-May, and If I was to buy now these are the ones id consider:

X300 XJR - Linked above
X300 Sov 4.0 - http://www.autotrader.co.uk/classified/advert/201702011884587?onesearchad=Used&onesearchad=Nearly%20New&onesearchad=New&radius=1500&advertising-location=at_cars&make=JAGUAR&postcode=s188xy&sort=price-desc&price-to=3000&model=XJ&page=1
X300 Sov LWB 4.0 - http://www.jagwestlondon.co.uk/vehicle-details.php?vehicleID=11807&uid=4
X300 Daimler LWB 4 Seater (Rare) - http://www.ebay.co.uk/itm/1996-DAIMLER-SIX-LWB-AUTO-FULL-HISTORY-RARE-MODEL-WILL-APPRECIATE-VGC-BARGAIN-/142296156117?hash=item21218307d5:g:kPcAAOSwr~lYtVII
X308 4.0 Sov - http://www.ebay.co.uk/itm/Jaguar-XJ8-4L-V8-Sovereign-with-Over-7k-of-extras-from-new-F-J-S-H-/112325558160?hash=item1a271fff90:g:zR8AAOSwB-1YvR5Q
Daimler Super v8 - http://www.ebay.co.uk/itm/2002-Daimler-Super-V8-LWB-/262864107514?hash=item3d33ebf7fa:g:iREAAOSwTuJYszna





P700DEE

1,107 posts

229 months

Sunday 19th March 2017
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If it were my money I would only be considering an X308 XJR. The X300 is supposedly the more reliable but at the age these all are now rust is your biggest enemy. The XJR has the better Mercedes 5 speed box compared to the ZF five speed in the XJ8. I drove an X300 XJR as a loan car when my XKR was in for service and as shocked just how poor it handled and how much slower it was. The X308 is a step up in refinement over the 300 and you definitely want an R wink
There are a few in budget on the bay so time to go see a few and drive them. There's a good guide on here for what to look for but Nikasil is a dead issue now, water pumps will have been changed in the last 17+ years and even the tensioner issues are not as dangerous as some make out.

Jaguar steve

9,232 posts

209 months

Sunday 19th March 2017
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I've done tens of thousands of miles driving both.

Like for like the AJ16 engine in the X300 is nowhere near as smooth and refined or powerful as the V8 in the X308. They're absolute chalk and cheese IME and Jaguar ought to feel quite embarrassed over that particular engine, especially when the contemporary mid 90's BMW 6 cyl motor was so gorgeously lovely.

In the real world the V8 uses a little less fuel too. The 6 cyl cars are further hampered by a really agricultural 4 speed gearbox that has a way too wide a spread of ratios and doesn't engage either top gear or converter lock up unless you're over 50MPH. That means you chew an outrageous amount of fuel whilst driving round town or when trying to make fast progress or in hilly areas whereas you can drive a V8 under the same conditions without hammering fuel anywhere near as much.

Both cars are fine for gentle wafting so long as you're not expecting Citroen like ride quality but IMO the V8, providing you buy carefully and you're prepared for a little preventative maintenance, is a vastly better car to own and drive all round.

Alster370

Original Poster:

10 posts

84 months

Sunday 19th March 2017
quotequote all
Thanks for the input so far guys,

Ive gone though pretty much every X300/X308 thread on the internet, so im aware of the overall conclusions that the X300 is simpler, cheaper to maintain, has more charm and is more reliable, whilst the X308 is quieter, more economical, better handling and more refined in several aspects.


Im leaning towards the X300 mainly because of the engine, in that the stroke is larger than the bore, so you get lots of lazy torque, which is partly what I like in my current diesel. As far as refinements go, I care more for quietness, smoothness and the absence of creaks and squeaks. The X300 sport I drove was fine in my view, the only gearbox quirk I noticed was a bit of a jerk when operating the kickdown in sport mode.

Im not really looking for the jag to have any kind of sporty handling, the softer the better, I almost wish I could put it on those gorgeous 15" 70 profile donut wheels from the 1 series XJ. The faster it is the better, the softer it rides the better. Thats why my ideal choice would be the super v8, as its the speed of the XJR without the harsh ride, which was why I was curious if the suspension from a sovereign could be used on a X300 XJR, to achieve the same effect, as Daimler didnt do a super I6 unfortunately, and as far as ive read, its quite a task to swap in a SC AJ16 into a non SC car.


Jaguar steve

9,232 posts

209 months

Sunday 19th March 2017
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I can't see why you shouldn't be able to fit touring or comfort suspension to a XJR. It's a lot of work though as you'll also have to consider replacing all the bushes whilst it's all in bits and find out if the anti roll bars are the same diameter and spec. too. You'll need to fit 16" wheels and 60 profile tyres to get the full benefit and have a geometry reset as well

I'll leave it up to you to decide whether you really want XJR BHP with Sovereign handling in something the weight and wallowage of a X300...

There's not enough clean pairs of pants in my underwear drawer so I wouldn't.

Alster370

Original Poster:

10 posts

84 months

Sunday 19th March 2017
quotequote all
Jaguar steve said:
I'll leave it up to you to decide whether you really want XJR BHP with Sovereign handling in something the weight and wallowage of a X300...
I appreciate what your getting at, I wouldn't be planning on taking corners at any speed, maybe just showing up some BMW drivers haha. I took some inspiration from that guy who put an XJR engine in a series 1 XJ.

If I get the right XJR I reckon it could be a good result. Any XJR that is ~£1500-2000 chances are either it needs paintwork, interior work or the suspension is worn though. If I can pick up one which just needs a suspension renewal then I can just replace all the suspension at the same time with the sovereign units. Got a least £4k to play with at the minute so could probably even replace the interior as well.

a8hex

5,829 posts

222 months

Sunday 19th March 2017
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Alster370 said:
a8hex said:
While the wood work and carpets are black the rest of the sports interior doesn't need to be. I'm pretty sure the same choices were available on the X300 XJR as they were on the X300 Sport. My Sport has the ivory leather so a lot of the interior is light.
As far as I know you can get a sport/XJR with walnut/oatmeal interior, but its rare to get a sport/XJR that doesn't have ivory with black wood, ive only seen one, might go test drive it actually.
http://www.autotrader.co.uk/classified/advert/201701211536837?price-to=5000&sort=price-desc&make=JAGUAR&radius=1500&advertising-location=at_cars&postcode=s188xy&model=XJ&onesearchad=Used&onesearchad=Nearly%20New&onesearchad=New&page=1

a8hex said:
If you want ride comfort then for the X300s there were 3 levels. When I tried them back when they were new I found the XJR was rather firmer than I wanted to live with. The Sovereign was softer than I wanted. The Sport's suspension was, for me, the Goldilocks level. They made 4L versions of the Sport, so you might want to add that to your list.
The last Jag I drove was a 4.0 sport, was nice and comfortable and handled bumps pretty well, but was one in need of TLC so Im not going to judge all sports on that example alone. My main objections to the sport are the lack of toys + the normally black & ivory combo, I prefer the seats in the sovereign too.
That XJR might have been a special order, the brochures don't list that as an option, Sports and XJRs were standard fit with the stained maple interior and no options shown. I'll hunt back through the filing cabinet to see what I've got from when I bought my X300. Jag-lovers has a some brochures, I thought they had the full set for the X300, but I can't see the colour chart for the Sport/XJR.

here's the URLs.
http://www.jag-lovers.org/brochures/xjr95.html
http://www.jag-lovers.org/brochures/1990_section.h...


a8hex

5,829 posts

222 months

Sunday 19th March 2017
quotequote all
Jaguar steve said:
IJaguar ought to feel quite embarrassed over that particular engine, especially when the contemporary mid 90's BMW 6 cyl motor was so gorgeously lovely.
The BMW 6 cylinder of the time was only the small one. I quite liked the x23 sized version but the x28 wasn't as smooth. To compete with the AJ16 you'd have been looking at the BMW V8s, at least in the 7 series the smaller version was painfully under torqued, it needed way to many revs to do anything and even then was so slow compared to the 3.2 XJ. There didn't seem to be anything to separate the 3.2 Jag from the 4L 7 series a friend had. The smaller version wouldn't even keep up with the Mrs' diesel.
The larger blocked BMW straight six belonged to an earlier era.

Alster370

Original Poster:

10 posts

84 months

Saturday 1st April 2017
quotequote all
Are there any specifics to how they made the x308 quieter? Ive searched and cant find much besides that the door seals are different on the x308, and obviously the door cards are different, so might insulate the cabin better, but I cant see why I cant replicate this on the x300. Other differences could be that the revised suspension better insulates from road noise and bumps?


Jaguar steve

9,232 posts

209 months

Monday 3rd April 2017
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Alster370 said:
Are there any specifics to how they made the x308 quieter? Ive searched and cant find much besides that the door seals are different on the x308, and obviously the door cards are different, so might insulate the cabin better, but I cant see why I cant replicate this on the x300. Other differences could be that the revised suspension better insulates from road noise and bumps?


The V8 engine is vastly superior in terms of NVH compared to the AJ16, especially at higher RPM. I'd say by some distance that's the most significant difference between the X300 and X308.

Jaguar steve

9,232 posts

209 months

Monday 3rd April 2017
quotequote all
Jaguar steve said:
Alster370 said:
Are there any specifics to how they made the x308 quieter? Ive searched and cant find much besides that the door seals are different on the x308, and obviously the door cards are different, so might insulate the cabin better, but I cant see why I cant replicate this on the x300. Other differences could be that the revised suspension better insulates from road noise and bumps?


The only way you'll get a X300 to X308 levels of silence and refinement is either by buying the V12 version or by putting a V8 engine in one.

Back in the day both cars will have been road tested on exactly the same P6000 or P4000 factory fit tyres and most of the suspension bushes are identical so the reduction in NVH has nothing to do with road noise transmission. The V8 engine is vastly superior in terms of NVH compared to the AJ16, especially at higher RPM.

Anybody would notice the difference between the two cars in just a few minutes driving..

Alster370

Original Poster:

10 posts

84 months

Friday 5th May 2017
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Thought Id give an update. Ended up bringing a turquoise 4.0 Sovereign 1995 from Dorset back to Sheffield two weeks ago, got it for £2500. Several problems, but overall condition is good for the price, and the interior is excellent. Been doing some general servicing, so new plugs, filters etc but have been trying to get the cause of this lumpy idle sorted out, which was there when I bought the car. Doesn't affect actual driving, just idles poorly, as if one cylinder isn't firing properly, you can hear it pretty definitely at the exhaust end.

I've got a code of P1621 from a cheap reader and had a look at threads and some seem to be resolved by replacing bad coils or crankshaft position sensors.

Can anybody offer some help to narrowing this problem down further?


Jaguar steve

9,232 posts

209 months

Monday 8th May 2017
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If the crank position sensor is faulty the engine won't run at all. If you have a faulty coil that particular cylinder won't fire.

If you have a lumpy idle I'd start by checking the entire induction system and all the vacuum connections downstream of the MAF for air leaks.

Alster370

Original Poster:

10 posts

84 months

Monday 10th July 2017
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Been a while so I thought Id give an update. Rough running is still there, but its only in park for 95% of the time, ive been told its most likely clogged injectors. I also have poor response in park, hard to test in drive, but in park when stamping on throttle from idle the engine almost chokes out then catches up eventually. Unplugging the MAF makes the idle 10% worse but response is miles better. Couldn't find any vacuum leaks, so Introduced one by taking one of the manifold lines off, and rpm increased by 150-200 rpm and idle improved slightly.

To give you an idle of this hesitation, using this video of a 3.2 revving as an example https://www.youtube.com/watch?v=QLBOH-G9f5g
from idle to 2000rpm, my car takes 40 frames, with the first 9 of those with the revs actually dropping after the throttle is pressed, corresponds to maybe a 150rpm drop, whilst the video car only takes 21 frames with no initial drop. (Both videos were recorded at the same fps, 25 I think.)

Any ideas?

Mike daily

11 posts

80 months

Tuesday 11th July 2017
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Hi alster370, my x300 devolped a rough idle and slight missfire, but was cured with new coils, have a look at yours and if any signs of cracking are present I would replace them, (4 of mine were badly cracked) if they are original then they probably will be cracked, there's a lot on the forums about x300 coil issues, while the coils are out look at the magnesium valve cover in the spark plug wells, as an arcing spark can munch away at the valve cover, and check for oil sitting around the plugs.check stuff like plug gaps and air filter, also perhaps check maf is not dirty too. Throttle bodies can get clogged up with black gunk , and as mentioned unmetered air leaks too. Hope this helps

londonbabe

2,044 posts

191 months

Tuesday 18th July 2017
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I remember a quote from someone at Jaguar describing the AJ16 as having "the power of the Lexus V8 and the refinement of the BMW 6 which is the exact opposite of what we would like"

a8hex

5,829 posts

222 months

Tuesday 18th July 2017
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londonbabe said:
I remember a quote from someone at Jaguar describing the AJ16 as having "the power of the Lexus V8 and the refinement of the BMW 6 which is the exact opposite of what we would like"
Well the 3.2 AJ16 was miles ahead for the BMW 3.5 V8 around at the time both in terms of refinement and usable torque delivery, I expect it was in usable power delivery too. Certainly my X300 was miles faster than a mates 735 but then even LadyB8's 320CDi Merc was so perhaps that isn't saying much. It also felt quicker than the 535 I test drove. In terms of usable road acceleration the 3.2 X300 was pretty much identical to another friends 740.

Jaguar steve

9,232 posts

209 months

Tuesday 18th July 2017
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londonbabe said:
I remember a quote from someone at Jaguar describing the AJ16 as having "the power of the Lexus V8 and the refinement of the BMW 6 which is the exact opposite of what we would like"
I was working as a mechanic at a multi franchise car dealer when the first version of that engine was launched in the 3.6 XJS and a little later in the XJ40. My experience both then and later putting some 50k miles on my own X300 is it's a horrid engine in terms of refinement.

Not even close to either the previous ancient Jaguar XK engine or the later gorgeous V8s and behind any contemporary six cylinder motors from BMW, Rover or even the Renault/Peugeot/Volvo 2.7V6