Engine shaking

[Tomsjagpride]

So I bought a 1995 jaguar x300 4litre straight 6 automatic about three months ago when I bought it it'd been sat for over a year and the battery was flat so I replaced it with a brand new heavy duty one it already had old fuel in it so gave it a shot at firing it up after two hours of wishing and hoping we finally got her to fire up and left it ticking over it didn't sound great obviously and also had a blow in the exhaust so once it had warmed up etc I got the car moved to a different location for me to work on it since then I have....had the windows tinted had the wheels re aligned by kwik Fit polished the hell out of it put brand new spark plugs in it I have also fixed the blow in exhaust had it motd and taxed etc replaced the grill the wing mirrors the emblem on the bonnet and all was great until the other day I put my foot down for maybe five seconds got it home all fine then the next day I started it up and the engine was shaking like hell but no strange noises or lights on dash etc so turned it off later that day started it again and all was fine so half way to work stopped at a shop got back in the car it was fine drove almost to work and as I stopped at the lights it started spluttering like it was going to cut out then I pulled away and it was rough sounding with almost no power so naturally I was nervous about getting home after work...once my shift was over I went back to the car turned it on and it was shaking again for maybe 10 seconds then stopped so I put it in drive and drove home and the car ran like a dream again....any ideas as this seams intermittent?????

[PeterDavisX300]

The first thing David Marks would say...................."What plugs did you put in?" These cars like to run on 'Champion' spark-plugs, the engine can be quite fickle about this. Next thing to check would be the MAF sensor, take it off and give it a good clean with Carb'-cleaner. After that, injectors off and check the seals. I suspect that it sitting for a while would be the cause, perhaps a good long run with a frsh 'High-Octane' fuel, personally, I never use 'supermarket' fuel. Let us know how you get on.

[poprivet]

Certainly sounds like a cylinder is cutting out. Does the '95 have the individual coils on plug? They can fail.

[PeterDavisX300]

Certainly sounds like a cylinder is cutting out. Does the '95 have the individual coils on plug? They can fail.

Yes. See if you can get a known working coil to check one cylinder at a time. You'd need to use it over a length of time. The coils get very hot down in their little 'hollow', you might check for cracking. One of mine is cracked though, and still working perfectly. Keep in touch with what you're attempting, it can be a long process!

[Tomsjagpride]

Up to now I've cleaned the air filter and the sparks plugs are NGK PLUGS I did use a bottle of redex injector cleaner which mixes with a full tank of fuel it's so confusing for example I drove the around town most of today and not a problem in sight then I let my dad use it to go to work and asked him to let me know how it went and he said it was fine until he got half way there and it started shaking again in idle and had power loss for a few moments then was fine again

[Tomsjagpride]

And yes it has 6 individual coils there's a guy selling them for 8 pound each on eBay original parts too but I'm not sure if they come with the gaskets he hasn't specified or replied to my email

[PeterDavisX300]

Get a couple of those coils if you can, then swap them out one at a time starting at number one cylinder. Don't forget to clean the MAF, after that you'll need to check the injector seals nearest the tip.

[Tomsjagpride]

So I've been up today and took out the air filter the mass air flow sensor and the throttle body and they have now all been cleaned with engine and throttle cleaner and it's made a massive difference to the driving experience and throttle response my main thought now is that it's got to be spark plug related / coils so gonna source an extension bar for my socket set and give that a go plus I've now ordered six champion spark plugs of eBay so fingers crossed and I will post any updates

[PeterDavisX300]

Remember to put the spark-plugs in 'correctly' with a very nice gentle torque that squashes the gasket nicely! A tiny-teeny, bit of 3-in-1 type oil on the threads will allow them to run down into the bore nicely. Get gaskets for the coils from ebay, they should be ok, and cheaper than JLR. (I don't get many cheap rubbish stuff for my cars off ebay, but stuff like that should be ok) There is also a 'bellows' type rubber large pipe that connects to the 'Inlet' side after the MAF. it has an EGR pipe coming from the rocker-cover. This can also get quite 'gungy', get it cleaned out. If the car has sat for a while and been occasionally started, then there may be a build-up of moisture, this leads to emulsion. If your not sure of the 'bellows I'm speaking about, tell me and I'll try pic it the morra. Happy-solving.

[ChrisDixon]

If it ain't bad fuel, the coils or the plugs .... intermittent problems can often be a warning the crankshaft position sensor is on the blink. Causes all sorts of odd symptoms including engine shake.

[ptjs1]

Tomsjagpride,

You've mentioned changing a number of parts but no mention of fuel filter. These AJ16 engines hate clogged fuel filters. If you don't know if it's been changed recently, just change it anyway.

Good luck

Paul

[Tomsjagpride]

So I've now ordered the new coils gaskets and champion plugs and hopefully next week I should have enough to get a full service done on it...it is a shame because other than this shaking issue now and then it's a lovely car to drive just cruises along and turns a lot of heads on the way since I bought it in total I've done ....brand new battery / new grill / new emblem for the bonnet / all new bulbs right round / new stereo / tinted windows / I've resprayed the roof and bonnet and clear coated also/ had the wheels re aligned by kwik Fit /new centre caps /new wing mirrors also I want to get a new roof lining as I've removed the old sagging one/fixed all blown fuses and the passenger side window motor and wind screen wash motor....it is slowly getting there and it's great getting to work on it with my dad as he always had old jags from when I was young so enjoying the whole project so far lol

[PeterDavisX300]

Where are ya Tom? What colour roof-lining ya after, I've got a new full Jaguar kit that I reckon I won't use because it's been in the loft for Two years. Mines the grey one. If you get a new Crankshaft Sensor, go for a Lucas one, about £60. Not a cheap one or second-hand.

[Tomsjagpride]

I'm in Liverpool peter could do with the roof lining to be honest lol I've been back to the car today and took all the coils out and discovered not one of them had a gasket on I never bothered to look when I done the spark plugs but it looks like the previous owner has used bathroom sealant instead of buying new gaskets for the coils so sorted that out today and car seems fine so far

[Tomsjagpride]

And yeah a grey one would be fine peter anything beats bare fibre glass dropping on your head lol