Were these two recent failures the same brand? Maybe even the same vendor?

It can be a troubleshooting nightmare to get new parts bad from stock. And then have it happen twice? Sounds far-fetched, but I've had it happen to me. Without thinking, I got the second replacement from the same source as the first. I think the vendor unknowingly had a bad batch sitting on the shelf, and the second replacement failed just like the first one. I've learned the hard way to go with a different source to avoid getting the same bad batch.

 

Hi
Yes same brand same supplier. It seems to be a re-badged Bosch pump. Which puts me off the Bosch too.
Upon opening the first of the new failed pumps it smells burnt. The plastic has scored itself as it was spinning. It seems it was simply too tightly together or something, no tolerance to expand so it heated and melted as it rubbed itself while spinning. What made me suspect the pump was the source of the heat was the pipes were cold.

Planning next move, but it maybe a 2nd hand OEM Hella or something.

 

Quick update.
So both of the new AVT (re-badged Bosch) pumps are totally dead and smell burnt. The newest one was so badly seized it will not turn at all after dismantling.
It could be a bad batch, but I would not recommend anyone use the AVT or Bosch pumps.

I have a replacement OEM Hella and only time will tell,

 

Hi All, Update again.

I thought I had posted this already but maybe I typed it in and then forgot to hit the post button. Sorry if this appears twice (slightly different text).

We went out for an approx 100-mile drive, all ok until the last 25 miles then the original Restricted performance came up, P2601 so we pulled over to the side of the road.
The fuse was ok, the pump was running, the pipes were hot to touch, pump not too hot.

Is it possible the IAT2 sensor is faulty or out of spec being near 20 years old?
What is the part number to order a new one?
Is it LRA1600BA?

If not please could somebody advise?

What are your thoughts on the sensor causing the fault? All is ok again once the error is reset, but then it randomly comes back.
Thanks

 

Maybe

AJ83678

?

 

I suppose any sensor can fail or go out of spec, though that one hasn't - so far - proved a problem.

 

That is true, possibly...
We have unplugged it and cleaned the connections and sprayed.
Maybe that is all it needs.

We need to bleed it again and bring it up to temp on the driveway. Then its just another longish drive it needs to see if it bring up a problem again.
Cheers

 

I suppose an air lock / insufficient pumping might well throw that code.

 

Have you done a cooling system pressure test?

On my '02 V6, twice I've had minor leaks that didn't leave any external signs, but I did notice the heater performance dropped off. I think it had something to do with the pressure not building up to the normal range and this affected coolant flow somehow. The system is fairly complicated, with lots of different passages, even more so with a supercharger.

In both cases, the leaks were up high so it was mostly air escaping, not coolant. I fixed the leaks and the heater operation returned to normal. Coolant loss was minimal.

I wonder if something like that could be happening, affecting the coolant flow. A pressure test is quick and easy, and will find leaks that aren't otherwise obvious.

 

My feeling is that pressure won't be any problem (not least because the SC coolant circuit is almost entirely separate, just shares the reservoir).

Also, I've run my car with no coolant reservoir cap on occasion and not had any code flag.

 

Update time.

All seems to be running ok. New pump fitted again (for the hell of it) and bled cooling system after a top up through the supercharger port.
Test drive seems to suggest all is ok, however it took 70 odd miles to generate an error last time.

We also cleaned off the IAT2 sensor's connector pins and sprayed them with an electrical contact cleaner.

Time will tell.
Thanks

 

Another update:
I got the P2601 Restricted Performance error again. Stopped, and checked the pump, it was running.
Last time extra care was taken when bleeding air out and all seemed perfectly good.

I am starting to think the IAT2 sensor is causing some false alarms.
Does anybody know if the IAT1 and IAT2 sensors are the same? If so could they be swapped to see if the fault moves?

Thanks

 

Iat1 should be part of the maf sensor. Iat2 is stand alone on the passenger side intercooler at the rear of the cooler matrix towards the rear of the engine on my 06 str. I think mine screws in

 

If not interchangeable, a new IAT2 sensor would be a reasonable gamble at this point.

One quick thought: Do you have a scanner? Is IAT1 showing a reasonable temperature value? It should be close to ambient.

Among other factors, the computer monitors temperature before (IAT1) and after (IAT2) the intercooler. If the upstream sensor is bad and showing too cool, that could trick the computer into setting this code because the downstream side erroneously appears too hot for conditions. It won't flag the erroneous upstream sensor, as it simply thinks it's a very cold day.

Years ago, I was taught computers are very smart but can be very stupid at the same time. Unlike you or me, the computer may not even question -20F intake air in the middle of summer.

Might be worth confirming before trying a new IAT2.

 

I may have missed this but what is your iat2 temp. The scanner may read it as iat only. A good rule of thumb is120 degressf plus ambient temp is the temp leaving the charger. Cooling by the intercoolers should be about 80 to 90 degreesf. Leaving you the iat. Ex. 90 degree day plus 120 = 210. Take away 90 for charge coolers and you get 120 which should be close to a degree or two to your iat. The other day it was 106 while freeway driving and my iat was 130. 106+120= 226 - 96 cooling degrees = 130 iat. That is very efficient supercharger cooling system for factory

 

I think i replaced my number 2 sensor when i had the charger off. It is doable with the charger on. Make sure you verify if it is threaded in or has a base with 2 screws. Then order accordingly and verify using the parts diagram

 

Thanks

I have had problems finding the part number for the IAT2 sensor.

Are there different ones based on year? Ours is a 2004.

Thanks

 

IAT1 temp a the MAF is readable with my scanner (iCarsoft LR2 for Jaguar and Land Rover) but it will not read IAT2. From memory IAT1 temp is never abnormally high, yes I agree it should be close to ambient, however, I will check again.

I have tried adding the S Type R profile for Torque to my Torque setup, but that is not working at all so I need to work on that as a separate thing. If I use a standard profile all is ok, but it does not read IAT2.

Thanks

 

Ok I think I have found it.
Please could anybody sanity check this for me?

• SKU:AJ83678
• Other Names:Air Charge Temperature Sensor
• Description: XJ, XK. Sedan. S-Type. 4.2l. With supercharger.

Thanks

 

I was mistaken on my 06 str. Mine sensor looks just like the part you are looking at. You should be good with that one. When i ordered they sent me the thread in style. Apparantly the 2 screw one supercedes the threaded one with the same part number. That is what i recall the story being. What iat temp are you seeing regardless of location