When I pulled my cam covers to change the tensioners I saw more oil residue/light sludge than I expected, given the regular oil changes. The VVT's were a bit crusty. I can clean the top end, but my concern now is wether or not I'm getting proper oil flow throghout the engine. I've read horror stories about engine cleaners ruining engines. Is there a safe way to clean out an engine? Can I accomplish anything by dropping the pan and inspecting/cleaning? Car runs great, no smoke. I used a little oil but was probably due to leaking around one cam cover and the VVT seals. Should be ok when I seal her back up.

Bart
2000 XJ8 130k

 

Bart, I have used engine cleaners in my truck a few times to help with a valve rattle issue. I personally fail a bit conservative. When it comes to engine cleaners, you will notice they come in 2 flavors, you have the 15 minute ones and the 3000 mile ones. I tend to buy the 3000 mile ones and then about 30-50 miles before I decide I am going to do an oil change, I toss the detergent into the engine. Then, right before the oil change, I make sure to run the car good to stir up as much stuff as I can and get the oil nice and warm. This will help ensure that any residue that you can flush out is going to come out. Do your normal oil change (make sure to replace your oil filter), maybe taking a little extra time to ensure all the oil can drain out. From there, refill and you will be just fine. I use a product called CD2. Comes in a yellow bottle. But, should be good with the BG line of products too.

 

I personally have used cleansers on my vehicles before, and there are a couple of things to keep in mind. Some of the more aggressive solvents are not real nice to rubber. Almost all oils have detergents in them, and the purpose is to suspend the dirt and other contaminates in the oil until filtered/changed. The key to assist you in cleansing an engine is frequent oil changes. You can get aftermarket products that add additional detergents/solvents to the crankcase, but remember that all that garbage then becomes suspended in the oil and more frequent oil/filter changes would be to your advantage. Once oil has coked inside the engine, it will be tough to get it out.

(Disclaimer: While I am an ASE Certified Master Tech, the following suggestions should be considered carefully and misuse of chemicals can and will damage your engine.)

Over the years when I pick up a high milage XJ's I generally perform the following procedures. I get a can of GM Top Engine Cleaner, or Mopar Combustion Chamber Conditioner and remove the plugs and spray/pour a couple onces directly into each chamber through the plug holes. This is a highly aggressive solvent, so care must be taken to not get it on other parts. (I use a very small funnel to get it in) Slowly rotate the engine by hand a couple revolutions to allow it to get around the rings. (stuff rags in plug holes or you will spray the solvent everywhere) Allow to set overnight. Next morning I place the plugs back in, and pour in a 15 minute runtime oil cleanser. (My suggestion is BG) Nasty smoke and smell will ensue on startup so make sure you are in a good ventilated area. After the cleaning, I drain the oil and replace. At 1000 miles I then replace both oil and filter again. This time I add a detergent modifier and drive the vehicle another 1000 miles and change oil/filter. After that Mobile 1 every 2000 for the next 10,000. I add one can BG 44K at the first fillup, and when that tank is empty, a can of Techron to the next couple of tank fills.

Bart, you never told us how the vehicle runs after your secondary tensioner change...

 

Thanks for the advice. Since the car has ben running great I may skip the cleaning or at most use a 3000 mile cleaner. As far as the tensioner change I'm still waiting for the parts to arrive in the mail. Will report results thereafter.
A side thought. I have owned the car since 03 and looking back it's been considerably more reliable than I would have expected. Other than a transmission change at 60k which I don't like to talk about, I think I'll I've had to do is replace the thermostat, a heater hose and a couple relays - along with normal wear items. Not bad for a "luxury" sedan with a reputation for having reliability problems.

 

Any thought on the oil pan? Is there anything to clean in there?

 

Bart:
While DBX and Thermo gave what seems like great advice for a dirty motor, since you mentioned regular oil changes, and if you have really done that, then I would get on synthetic oil. Then worry about health care or something besides the little bit of varnish in the top of the engine.

 

Bart, concerning the oil pan, any parts of your primary and secondary chain tensioners that have broken off eventually end up there. Can also be drawn into the oil pickup screen. Sludge ends up there. Remember oil filters can only hold 10~20 grams of junk and then go into bypass which means the suspended garbage goes right to bearings.

While it would be great to remove all the varnish/sludge from the engine, it is more important to understand how it got there. Obviously not changing the engine oil regularly ends up creating slude, but oil mist inside the engine creates varnish, and hi-temp and stop and go makes it worse. Blow-by from the combustion chamber is really a bugger as well. That's why I do a really good cleaning on the rings. The engine cleansing is not so much to "wash" the inside, as it is to restore, as best as possible, the operation of the compression and oil control rings.

There are some shops you can find that are equipped with BG's Power Flush system, which uses externally connected equipment and even air-blows the cleanser and residual oil out of the engine, and then primes the oil system before restart.

Is it worth dropping the pan? Well, that's a call you would have to make.

 

Look into Auto RX, lots of info on Bobistheoilguy website. I did it in my 98 VP 82,000 miles it worked great.

 

Forte is a manufacturer that is recomended by Jagura and they have lots of "Hokus pokus" stuff to put in n engine.

We used there engine cleaner on severall ocasions when i was working at a Jaguar workshop.

The oilflush did some wonders on old XK engines where the compression was uneven

So that it works I can guarantee

Now i work at a volvo dealership and we use Protec cant say that it is as good as the Forté products was but i probably works aswell