Hi, just wondered if anybody could shed any light or suggestions.
I've got a customer with a Jaguar XKR 4.2 Supercharged.
Almost everything is invisible or inaccessible, low side port access requires removal of part of the inlet manifold, so I've strayed from doing this.
I originally visited, 4 weeks ago... Nitrogen pressure tested it, I pressurised it... Then allowed the pressure to stabilise, as I've found that sometimes as pressure bleeds from high to low side pressure will appear to drop without a leak... So waited for it to stabilise... The pressure held fine.
Used bubble spray on anything I could see, no leaks found.
Vacuumed it down, vacuum pulled down fine and micron reading pulled down to 1500 microns easily.
Vacuum also appeared to hold.
So I really couldn't find a leak, but today I was called back as Aircon wasn't working, when I checked it system was completely empty bar 20g so it had lost 680g in about a month.
Went round it again today in more detail, same as before on leak tests... But this time used an electronic leak detector which is supposed to detect a leak as small as 1/10 oz per year.
Moved it around the pipes and compressor connections and area... Nothing.
Only area it did seem to trigger was when I waved it around the condenser.
But it wasn't a constant detection, it was kinda like.. It would not detect anything then all of a sudden blip for a second then go back to nothing again.
Also noticed some black oily dirty patches at in the top corners.. Which I suspected is where air is rushing from below up between the condenser and gearbox rad (as condenser is sandwiched between a radiator either side... It's in the middle.)
Couldn't see full face or behind condenser because its covered by the rads, all I did was put the detector probe in the gap between.. So the lack of a constant detection and that I know airflow disturbance can cause small triggers of the detector.. As can just covering up the end of the probe. And lack of access to front and rear I was skeptical about taking the detector as evidence of knackered condenser.
So I've shoved some UV dye into the system now, and said I will go back in 1 week.
Will see what happens. Also screwed the high port valve cap down tighter to hopefully eliminate that also.
But if I can't find any UV dye traces and its still lost gas I am drawing a blank.
Reluctant to write off condenser, even though in back of my mind its a likely culprit... Because a condenser isn't something I wanna change on a car that expensive on somebody's driveway.. And they also seem to like jag dealers and genuine parts.
So if I write off the condenser, he takes it to jag and they say condenser is fine or fit a condenser which is genuine plus labour on top... Then it still leaks customer is going to be annoyed.
Just stumped for ideas and wondered if anybody could offer any help or advice.
Thanks.
I've got a customer with a Jaguar XKR 4.2 Supercharged.
Almost everything is invisible or inaccessible, low side port access requires removal of part of the inlet manifold, so I've strayed from doing this.
I originally visited, 4 weeks ago... Nitrogen pressure tested it, I pressurised it... Then allowed the pressure to stabilise, as I've found that sometimes as pressure bleeds from high to low side pressure will appear to drop without a leak... So waited for it to stabilise... The pressure held fine.
Used bubble spray on anything I could see, no leaks found.
Vacuumed it down, vacuum pulled down fine and micron reading pulled down to 1500 microns easily.
Vacuum also appeared to hold.
So I really couldn't find a leak, but today I was called back as Aircon wasn't working, when I checked it system was completely empty bar 20g so it had lost 680g in about a month.
Went round it again today in more detail, same as before on leak tests... But this time used an electronic leak detector which is supposed to detect a leak as small as 1/10 oz per year.
Moved it around the pipes and compressor connections and area... Nothing.
Only area it did seem to trigger was when I waved it around the condenser.
But it wasn't a constant detection, it was kinda like.. It would not detect anything then all of a sudden blip for a second then go back to nothing again.
Also noticed some black oily dirty patches at in the top corners.. Which I suspected is where air is rushing from below up between the condenser and gearbox rad (as condenser is sandwiched between a radiator either side... It's in the middle.)
Couldn't see full face or behind condenser because its covered by the rads, all I did was put the detector probe in the gap between.. So the lack of a constant detection and that I know airflow disturbance can cause small triggers of the detector.. As can just covering up the end of the probe. And lack of access to front and rear I was skeptical about taking the detector as evidence of knackered condenser.
So I've shoved some UV dye into the system now, and said I will go back in 1 week.
Will see what happens. Also screwed the high port valve cap down tighter to hopefully eliminate that also.
But if I can't find any UV dye traces and its still lost gas I am drawing a blank.
Reluctant to write off condenser, even though in back of my mind its a likely culprit... Because a condenser isn't something I wanna change on a car that expensive on somebody's driveway.. And they also seem to like jag dealers and genuine parts.
So if I write off the condenser, he takes it to jag and they say condenser is fine or fit a condenser which is genuine plus labour on top... Then it still leaks customer is going to be annoyed.
Just stumped for ideas and wondered if anybody could offer any help or advice.
Thanks.