2007 xc70,cooling fan running after a short while or at startup,and stays on....??

[volvoturboguy]

Hi All

Just a got an engine swap done,c/w new timing belt kit,water pump,seals,the engine only has 76,000kms ..looks good,runs great...even before leaving the shop I noticed that the cooling fan was on after a block worth of driving..the shop put it on the scope and found no codes,they removed the 2 computers inside the engine compartment,sprayed the contacts with cleaner, and did a hard re-boot,then it went off...this morning it's back to the same...
The car has been sitting for some time,but with the old engine it was not showing this issue at all.
The shop told us that the computer is for some reason requesting the fan to come on,the A/C is off and the engine temp is at the normal middle of scale,like always.
We were told to run it for a bit and it might resolve on it's own.
The fan does shut off after you turn off the ignition...
Any ideas?

Thanks

[hoonk]

Just a got an engine swap done

Was your old engine temp sensor (in the thermostat housing) swapped into the used engine that was put in?

[volvoturboguy]

No,this engine was from a rear hit 2006 XC90,the engine was still running in that,before it was removed.
I kept the original engine c/w everything that was in it.For parts I guess..
The donor engine came with pretty much everything.Turbo,intake,all the tubing etc.
The shop was very surprised to see that much on it,they usually come stripped from what he tells me.
The mechanic tells me that if the temp sensor is faulty,the fan runs for 3 minutes after you turn off the ignition ??

I suppose we can try and swap the sensor out and see if that is the issue.

[Willy]

The mechanic tells me that if the temp sensor is faulty,the fan runs for 3 minutes after you turn off the ignition ??

Mine does that often, I think it is normal.
Willy

[volvoturboguy]

Well..it turns out that the AC sensor was stuck,during the engine swap the AC had to be drained and then recharged after the install,when that took place the sensor that regulates the need for the fan got stuck and the fan would run all the time as long as the engine was on.
We took it back as requested by the garage 2 weeks later and it was put back on the scope and showed the AC system with readings in the 80's kpa..which they thought was a bit high but still no codes showed up.Codes apparently don't show up on the AC sensor..
We were asked to leave it for the day and today they drained the system,after refilling it the sensor reset and all is well.
The car was run through it's paces and the fan cycled as needed ..

Let's hope it stays that way,otherwise we will have to replace the sensor..