Hey everybody! Bought a "New" (2000 XJ Sport l6)It's throwing an engine code (p0455) Large EVAP and ran through all my hoses, they look fine. I also ran a smoke test with a cigar and a straw =P through all the tubes coming out of the purge solenoid. Only leaks were from the air box where it was missing a piece on the front (replaced with a cold air intake I had already purchased the next day) And leaking from the throttle body and the seat into the engine block head from the air intake (small ~1/2" hose) Also replaced my gas cap still has code up after about 40 miles of driving. Any ideas? I don't really want to blindly replace parts, and I'm not averse to taking it to a mechanic but I want to do it myself and learn how it works. Also some other general questions,

1) Throttle body spacer worth it?
2) losing coolant but engine never overheats, where can I find a schematic of the cooling system to look for leaks and what should be where. oil looks fine so I don't *think* the head is cracked (I have a haynes but It's not very descriptive in this category)
3)What other maintenance/tune up stuff should I do for this if I have very little history of what was done She's got 180k on her.

Sorry for all the nooby questions and thanks so much guys!

 

No. Those things are a gimmick that don't actually do anything. Save your money.

Uh oh. The 2000 and 2001 XJs came from the factory with the 0331 head, which is prone to cracking for no reason. Unexplained coolant loss is a major red flag that may indicate a head crack. This has been discussed here numerous times, so you should spend some time searching the board and reading up on the 0331 problem and how to diagnose a head crack with some certainty.

 

Thanks! As far as the cracked head goes, my oil before and after oil change and before and after adding coolant is the same level doesn't look like a chocolate milkshake and the engine never gets above 210 in temp. I took off the oil cap and tried to find a crack and after about ten minutes couldn't find anything. I'm not guaranteeing anything but without taking off the cover I'm pretty confident it's not cracked.

 

Update: Found a nick in my radiator hose bout a 1/4" long and a bit deep and definitely was leaking there, replaced, will see what happens from there.

 

for the p0455 I would maybe suggest to look at the gas cap.

 

Already did

 

I can't help with the evap code, but if it were me I would start with a search of the forums using Google, because this issue has come up again and again on the board. I was perusing some of it just now, and there appear to be a variety of causes.

"site:cherokeeforum.com large evap"

Maybe you'll get lucky and someone has had the exact same issue. At least that will give you some places to check.

 

Thanks man! I tried the search feature on the board itself but it was kind of vague and all stuff I had tried before but this is seeming to show me a bit more.

 

The board's search feature is terrible. That's not a reflection on the moderators. It's a weakness in most message board software.

Any time you need to search a message board, use the "site:" tag on Google. For example, adding "site:cherokeeforum.com" to the search terms limits the Google search to just this site. You can use that tag on any website.

I don't even bother with the built-in searches on message boards any more. The results from Google are almost always better.

 

You're a hero among men today shaky. I think I might have found something. I'll keep everyone posted.

 

check the hoses at/under the vehicle at the EVAP under storage area
My mechanic found a bad hose its a huge PITA to diagnose

 

Did you try checking these vacuum lines for a leak? Try spraying brake cleaner around them while it's running and listen for the idle to lower. Where you're spraying when it lowers is most likely where a leak is.

 

Not yet and I just bought some to try that. diagram helps alot thanks dude!

 

So after a long drive today I pulled over and coolant was boiling up through the radiator cap but the temp gauge is working fine and not going above 212. That's definitely where I'm loosing coolant but not sure why. Any ideas?

 

Radiator cap is probably shot. No big deal, they wear out. Replace it with a 16 lb cap. Stant/Carquest caps have a very good reputation.