I would try Restore first and see how it goes. It might fix the problem.

 

A 4 litre engine needs 4 cans of Restore for it to be effective. One can for every one litre of engine size.

 

Read the can for the recommended ratio.

 

I had this p[ropblem recently and solved it.
Search oil in the air filter by osyris.
The answer was
1- a broken part load breather tube , replaced in 1 hour
2- the part load breather orifice was cleaned to A DEPTH OF 45 mm..... I emphasis 45 mm.. this is the KEY to it.
Everyone jumps to the nikasil blowby issue... I have a 1999 car early AJ27 Niksil.. excellent performance.
The problem was an unknoweldgeable previous owner that caused this. He was a VERY nice fella, but he didn't care enough for the car to fix it. HE was anice chap, lucky I met him, otherwise I wouldn't have the car. I took a risk on it, it paid off.
best regards
Peter

 

So, can a blocked part load breather really cause so much oil to blow back into air box?

 

It can, but if you can see a gases, flowing from the oil dipstick - this is not a problem with a breather. This is a clear indicator of the problems with rings, pistons and liners. On a good engine there's no gases at all, just vacuum.
Also, it's bad idea to reroute breather from intake to the atmosphere - all seals will start to leak soon.

 

I've just found that the bit the part breather clips to has come away from the hole. It pushes back it and stays there bit should it be air tight?

 

yes it should be air tight.. check the part breather tube from the top cam ocver under the central air intakes and to the base of the throttle body and to the emmissions purge valve. THe tube has hence 3 connections. cam cover, throttle body area and emmissions tube.If any of it is NOT air tight then the throttle boddy is sucking in RAW air from atmosphere and not the gasses at the cam covers and emiisions purge valve. THis is what happened on mine and over time the crack part breather tube (due to a sloppy mechanic I presume) didn't suck in the engine gases and gunk built up on the inner breather orifice and cemented it up. From then on the engine could not breathe and the pressure exited through tot the oil filter.
Make sure the origifice is clean with a 2.5mm drill bit to DEPTH OF 45 mm.
The first time I did it I didn't go down that far and thought that the base was metal, then I pushed it in to 45mm , heard the carbon build up CRACK and it was opened.
No oil in air filter.
Such a small thing causes such a BIG problem and everyone jumps to the NIKASIL blowby piston rings crack path.

best
Peter

 

Good info from Osyris....which BTW he gleaned from me ;o))

Not only the Part Load Breather being blocked but the connections to both the TB and the Emissions Purge Valve wich is located on the firewall directly to the rear of the TB and slightly right.

This decice has three connections, a vacuum hose connected to a small 'T' piece, a larger hose that comes from the emissions canister and the biggest connection which is the other end of the Part Load Breather hose.
Check all these for security.

The emissions purge valve also has an electrical connection and quite often it's the fault of the purge valve causing a build up of excess oil in the intake trunking....combined with a lack of maintanace which all too often these cars are more and more being subjected to.
Cleaning of the PLB should be done around every 30,000 miles.
As these plastic hoses age, they become heat hardened and very brittle and should be replaced.

Too much faffle is spread about Nikasil which really is a dead issue these days as high sulphur fuel was phased out in the early 2000's.
In good mechanical order and well serviced, usinggood qauality oils and fuel, a Nikasil engine will out last a steel linered engine.

If ypou are really concerned about your engines condition, don't faff about and second guess, have a proper blow by test done by a competant technician.

 

Does anyone know where I can get a blow by test done in the Watford/Hemelhempstead area? (UK)

 

I think you would have better luck finding someone to perform a compression test. The Blow By test may no longer be available. I had only seen a Blow By test performed on video and that was the first and only time. If the engine is running fine I would suggest adding the Restore, each container is designed for 4, 6 or 8 cylinder and are marked as such.

I would also suggest not modifying any of the vacuum system on this car.

 

Right, I'm going to give the car an oil change and engine flush and put some Ametech Restore in it and see how that goes. I know the oil should be 5-30w but is it advisable to use a slightly thicker oil in my case and if so what one? Also would a thicker oil not have an effect on any hydraulics and the tensioners? Don’t forget I live in the UK where it’s not as hot as where most of you guys are from! And, if I am putting 1 litre of Restore, does that mean I put 1 litre less oil in?

 

First off never overfill your oil so when adding oil or whatever be sure to take it to the fill line of your dipstick. As for the viscosity for now I would stay with the 5w-30w and add the Restore and see what takes place. If you look in the owners manual you will see a oil type range that is regulated by ambient temperature, that is what is acceptable for your car. For my cars I use 10w-30w year round and I live in Virginia so it is acceptable by using the temperature range and to date I have not had a problem. In my truck Silverado 350 with 276,000mi I add a can of Restore and it runs just fine. If you want to know a little more about oil you need to use this link I will provide it has all the answers.

Link - Bob is the Oil Guy

 

wouldn't use any additives at all especially restore which is just
an oil thickener, as they all are.
The VVT variable valve timing system doesn't like it and you may end
up with a lot of error codes coming up on your dash.
Don't even use an oil flush it wll ruin seals.
Get the car running and wait till operating tempreture comes up on
the tempreture scale on the dash. Then while the engine is still hot
open the oil plug and drain the oil from the engine. THe hot oil
takes with it all the micro level particles which cant be removed when
oil is cold. Change oil filter right away while engine warm too.
Must be careful with hot oil.
Ensure breather tubes and orifice are clean and infact.. orifice clean
to 45mm wrt part load breather.
Engine shoul dbe good.
Oil additives with ruin emgine overall..sty away unless the engine is
known to be gone and you know it is indeed blowby.
best
Peter

 

You would be at odds with Brutal who has recommended Restore more than a few times.

 

I doubt Brutal adds much Restore at the dealership.

 

Where he adds it is immaterial.

In fact, if he goes to the trouble of recommending it and using it personnally even if unable to do so at the dealership, that would seem to be an even stronger recommendation.

 

If you say so, Mr. Plums.

I have a lot of respect for Brutal and I am VERY appreciative of his time spent helping us amateurs here, but his main interests on his cars is racing and modding, and not especially Jaguars. I assume he has a lot of experience on Jaguars and I know he has a lot of training on them. But none of that makes him an authority on engine oil additives. His opinion counts, but unless he has presented data of what benefits he observed in a road driven Jaguar after adding Restore, his is just an opinion. He ain't shy, so maybe he will offer his facts.

 

I am not sure you know Brutal well enough to make that statement. What I know about Brutal is that he is not one to promote anything that he himself has not used and verified to be worthy of using. As for Restore I have used it and would recommend it for Nikasil engines and blowby situations.

 

Gus:
Well, since you have used Restore and recommend it for Nikasil engines and blowby, then I would ask you- What specifically did it correct? Did it reduce the amount of oil that was lost between changes and did you compare Restore to just changing to say 20W50 oil? Was it a SC or NA engine? If it was NA, did any problemm with VVTs ensue? Was it an AJ26 or AJ 27 engine, since the VVT system is different?

And I ask these questions not because I have any bone to pick with Restore, I just don't see a lot of specifics as to how it helps, other than "well I use Restore and I have no problems!". Well, I do not use Restore and I have no blowby on either of my Nikasil engines either!

The other thing Plums has quoted Brutal on is use of a engine flush treatment. Again, I ask, for what benefit? Was it to fix a stuck ring? Did it work? On that one, I suspect there could be potential harm that should not be risked unless there was a specific problem you were trying to correct.

I am happy to be schooled on these matters, but only by facts and data. and, so far, I am hearing neither.