My XJR has done 70k miles when I bought it, and I tend to do relatively short journeys. I've heard about oil catch cans to help reduce the oil fouling on the valves. Are they worth fitting (and are there any recommended catch cans to use, and places to stash them in the engine bay on an XJR)? I've seen one video about them, but interested to hear from anyone who has done that mod.

Also, is there a way to try to clean the valves without having to take the SC off (again, I wish my indie had suggested that when I had the cooling pipes changed. Pretty disappointed they didn't suggest it tbh)

Many thanks

 

At 120K miles my intake valves weren’t that bad, but I brass wire brushed them anyways. There is no fuel additive that will help this because we are direct injected. You would need to spray it directly into the intake.

 

It it isn't such a big issue, I might not (fit one). It is quite a bit of work. Is there a way to clean the valves without taking the SC off? Are there any good products which can be sprayed into the intakes (with the air filters removed) to help?

 

In my opinion...not really. Even if you spray the fluid directly into the throttle body, it will get caught in the supercharger and then the charge air cooler fins before it ever touches the valves, so there will be no percussive cleaning action (think like how brake cleaner blasts dirt off rotors). Cleaning fluid will only flow through the system for 30 seconds or however long it takes to empty the can- that doesn't seem long enough to be of any benefit.

Caked-on carbon is tough. When I did this service (supercharger off), I rotated the engine until the valves in the selected cylinder were closed and then soaked them in carb cleaner, then manually agitated them with a brass bristle brush. I did this multiple times and still did not get the valves perfectly clean. The right way to do this is to walnut blast the valves, but that requires specialty equipment and the delta in efficacy between that and what I did is imperceptible.

 

Thanks @Jaaag_drivah Will leave it alone until the SC has to come off again.

 

I have installed an oil catch can. I collect ~ 4mL a month.

As far as cleaner, I have used CRC 05319 GDI IVD intake valve and turbo cleaner in the past. It caused a little bit of smoke to come out the tail pipes upon first use. I tried it again ~ 8 months later and got no smoke. So the smoke likely reflects some removable carbon coming off the valves, but hard to be sure.

 

Images of catch can placement and volume of oil captured.

 

Thanks for the pic. That's helpful

 

I have also installed a catch can onto my 2013 XJ Supercharged. I have a crank pulley and am tuned to approx 670hp. But personally I don't notice very much oil in the catch can even after 1500 miles. Maybe a few drops. Might be a good thing? However, I do notice a significant amount of smoke on deceleration, ie. when coming to a stop at a red light. Not always does it happen, but ever so often. Might need to add an additional filter to my catch can, just don't want it to affect flow. Then again maybe it's normal.. and I am only noticing it more because of my catless exhaust setup.