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I have a bit of bearing noise (I think) on start up which may be the smog pump, stops when it shuts off. Has anyone rebuilt one of these? I am about to drop front end and replace bushings, have a list of tasks to perform while things are accessible, this might be a good time to do this too?
My X305 is a car from the UK which I bought here in Australia from the seond owner who in turn bought it from the original owner in tthe UK and privately imported it.
It doesn't have an auxiliary air pump just an idler pulley, there is a vacant harness connector near it which must have been for the clutch. I presume the cars with air pumps must be programmed accordingly.
If you unplug the air pump on your car do you get a fault code?
I have never tried that, but undoubtedly the P0410 code would come up. The ECU is programmed for that required emissions protocol and would set the CEL.
Now - with a non-US ECU installed I could probably get away with it! I'm sure the ROW pulley would bolt right on in place of the pump. I could then delete the vacuum service valve, the air delivery valve and all associated piping.
The manual states that the hot idle air test is performed once per engine cycle but I notice mine is more active than that.
This characteristic of old-school emissions control is inconsequential when compared to what will be happening in the future, with many new state and federal mandates on the horizon that will shift the US into a "greener" future. As seen in the UK (and in OZ?) cars with larger engines are literally being taxed to death. My car is now considered a "rescue" from California, certanily the first state that will send out the "big engine" police.
When I do my front suspension rebuild I'm going to take a close look at the pump and see how rebuildable it looks as though it might be. Right now the underside of my engine is cleaner in places than the top, will be doing some sprucing up and fettling of various parts. New power steering hoses and fluids flush v high on list right now so it stops ruining the bushings.
Something that crossed my mind, I recently had my water pump off and the air pump idler pulley and associated bracketry had to be removed first to allow the water pump to be removed. There is part of the mounting bracket and also the tensioner mounting bracket that projects around to the front surface of the water pump and two of the water pump mounting bolts pass through both these parts. So if you eventually remove your air pump completely you will need to source two shorter bolts for the water pump.
Is it pretty easy getting the water pump out? I was planning on replacing mine while I have the car up and offline...hence my earlier rambling about the air pump. I'll keep my pump to avoid future bureaucratic smog nightmares...
Originally Posted by watto700
G'day Gents,
Something that crossed my mind, I recently had my water pump off and the air pump idler pulley and associated bracketry had to be removed first to allow the water pump to be removed. There is part of the mounting bracket and also the tensioner mounting bracket that projects around to the front surface of the water pump and two of the water pump mounting bolts pass through both these parts. So if you eventually remove your air pump completely you will need to source two shorter bolts for the water pump.
I had my front bumper off when I did my water pump work so that gave me a lot of good access to the air pump idler pulley and brackets etc. Once the brackets are out of the way then removing the water pump is straight forward. The fan has to come off first of course and one of the lower bolts is actually a large philips head machine screw. The water pump bolts are of several different lengths so it will pay to note where they came from. I also placed a sheet of thick cardboard on the radiator rear face to protect it from accidental damage. The metal of the core is quite thin.
I had my front bumper off when I did my water pump work so that gave me a lot of good access to the air pump idler pulley and brackets etc. Once the brackets are out of the way then removing the water pump is straight forward. The fan has to come off first of course and one of the lower bolts is actually a large philips head machine screw. The water pump bolts are of several different lengths so it will pay to note where they came from. I also placed a sheet of thick cardboard on the radiator rear face to protect it from accidental damage. The metal of the core is quite thin.
Been v short of time recently and the price of fuel in California has slowed my xj12 usage somewhat, keep trying to find time to get the front end down, out and serviced, hoses, belts etc.
My car is definitely making a rumbly accessory bearing type engine noise on start up for about 40 seconds, then something turns whatever it is off. The car is running absolutely perfectly otherwise, I'm a bit scared to mess anything up. I'm assuming as said previously it is the secondary air pump, but does anyone have any intel on what turns on and off when once you kick over the starter? I know I need new power steering hoses and have some lucas seal goop in the fluid as a temporary measure. After my starter motor extended replacement the fluid had dropped and there was a bit of squealing until the fluid worked its way around. Steering is perfect, no dead spots or weirdness.
Couldn't find any replacement v12 air pumps online, or any sort of rebuild kits....
It sounds as though my smog pump is on its way out. The car hasn't been started much for a few months after I did the entire front end, oil lines, sump gaskets. I'm getting a lot of noise from I think the smog pump until it shuts off, then what sounds like bearing chirps.
I haven't removed the belt yet to make sure this is what causing the noise, anyone experienced this? I'm still wondering if these things are self rebuildable since the Denso era units are annoyingly pricey.
Hearing a bit of lifter tick which I'll get to when I get into going through the top of the motor - underside all looks brand new, top looking shabby.
Cheers
Last edited by olivermarks; 06-22-2023 at 01:47 PM.
I'm now the owner of three smog pumps: the one that makes halloween noises on my '96 car, the one on left in the photo which is off the 96 xj12 scrapyard baller wagon and a '94 xj12 scrapyard find. They are all the same Denso unit. The 95 one has a noisy bearing so I'm going to take it apart and see what's inside to attempt a restore.
Hard to bench test these....wondering if ingesting dirty/oily induction air bungs them up internally...
I got the smog pump off the car- for those who need to do this:
Put car on low jackstands, take off driver side wheel (LHD)
undo the front of the plastic wheel arch liner pins and tuck up into wheel well
take front bumper off (two bolts and electrical connectors)
Remove the fan and shroud, protect radiator with card or wood sheet
Loosen the belt tensioner bolts on the front of the smog pump
put a wrench on one side, ratchet on other end of the long bolt through the smog pump, loosen nut
carefully loosen hose clamps on the red and black air lines, spray with penetrant before detaching
remove drive belt
undo electrical connector from loom at top of left side valve cover
Remove the long bolt towards radiator to free smog pump and lift out from top of car
The red and black hoses are PN EAC39542-SET, anyone been able to source new ones or equivalents?
The bearing on my pump seemed ok but a lot of crud fell out of the red line (air leaving pump) so I suspect it's bunged up with dirt inside.
I'm going to blow compressed air through it @25psi, see what happens....
I washed out my hoses but would like to put new ones on if possible, especially the red one.
I will dissasemble one of the junkyard pumps and share pictures soon
Pump in situ, two bolts that need to be loosened, bottom one comes out towards rad (protected by cardboard on left), top one is belt tensioner which needs to be disconnected from pump
Last edited by olivermarks; 05-07-2024 at 11:29 AM.
Some photos of pump disassembly, more to come when I have successfully reassembled Cover off Spring loaded vertical bearings shaft top bearing race two pump wings Using grease pencil to center pump wings
Last edited by olivermarks; 05-11-2024 at 08:16 PM.
In the end ensure there is not a check valve in the lines if bad throwing off your troubleshooting of final results
I don't have the V - 12 but the inline 6 does have 2 as an external from the pump and a pump internal check valve as the pump on the inline 6 is very different
Separate update on getting a car prepped for smog testing based on what I've found out so far:
I've established it would be possible to clean out the pump in situ before proceeding any further with repair or replacement.
To do this remove the water pump/smog pump belt. Spin/wobble the pulley to identify if this is the issue. If it is new bearing needed.
If not jack up car and remove left side wheel, find the smog pump inside the wheel well.
Remove the red and black hoses from the pump side. ideally get a vacuum cleaner in there to pull out any dirt form inside hoses. Check hose clamps for tightness
Put a 22mmm (I think) socket on the pulley nut, rotate pump and listen and feel for restriction.
Next blow compressed air through pump's top air inlet (that the black hose attaches to from air filter box) , rotating pulley nut slowly with socket. If a lot of dust blows out this may well be the central issue.
put everything back together and start engine, see if it has resolved any problems.
Last edited by olivermarks; 05-19-2024 at 01:17 PM.
After this I attempted to press the main rotating barrel bottom right in picture above to get to the bearing it spins on.
My 10 ton press ripped the ciclip through the lip of the housing.
I pressed form this side, the black shaft the clutch is attached to, hoping to get to the bearing, which is only active for 30 seconds or so on each start up.Here it is with the lip of the casing and the circlip. I'll probably jb weld the lip fragment to the case when I put it back together but puzzles how this was manufactured.
The important bearing, which is behind the pulley that is belted to the waterpump and crank is this one, which is in action the whole time the car is running.
I'll post best practice to replace when I put the pump back together but it's a separate process to opening up the case in theory. I got this out by using a piece of flat stock in a vice so I could break the nut free that holds the clutch on and get to the circlips.
By putting the case down so the flat stock slots into the spinning camber I was able to then put a breaker bar on the nut on the other side and break it loose. Might be possible to just clamp the pulley assembly to immobilize it to break the nut free also.
More soon
Last edited by olivermarks; 05-22-2024 at 11:49 PM.