Wanted to put this out there and see what eveyone thinks:

Heat + CPS = Failure

Here's why - I drove across NE last July pulling 10K lbs on a 105deg day. Truck never overheated but, I know things got "hot" OK - fast fwd about a month. CPS started acting up - Replaced it - truck ran fine.

I thought (at the time) oh it's just my time for a CPS failure.

Now - about a month ago I repeated a similiar trip - Oregon east to WY - Weather was colder but, Long heavy climb east through the mountains built up quite a bit of heat. (I had a cold front on but, partially open since I was towing 10k - took it completely off prior to starting the grade east of Pendleton OR & partially closed it once I was in ID)

Ok - It's been 4 weeks since that trip - Guess what! as of this morning -- CPS = Dead -- Hiccuped twice the other day on I5 then truck died @ a light this am.

Replaced CPS = Truck runs fine.

Is this just bad luck or, Could heat be part of the problem?

DG

 

I agree....that's VERY interesting. Have to give it some thought but u may have something there.
Nut

 

$.02: Mine failed San Jouquin valley July @ 107 F towing 10K trailer also. Bottom of first pull out of Sacto on I-80 east.

 

Thanks for the info!
Nut

 

Blue one or black one? I do a lot of towing over the summer, often in the heat. This has definately got my attention.

 

Check the air gap. It is very possible that the aluminum front cover has some warpage which could cause the air gap to increase. It is odd to see two new sensors fail in such a short time, regardless of color.

 

The 1st CPS failure I listed was actually the 2cnd one for this truck.

Mileage on OEM CPS = 20K Failed Nov 2002
Mileage on The 2cnd CPS prior to Failure = 35K Failed Sept 2005
Mileage on 3rd CPS prior to Failure = 6K Failed Feb 2006

All three were "Black" CPS'

How do you measure the CPS airgap? & what should it be?

DG

 

I have noticed that many trucks with bad cam sensors will run ok when the engine is cold but start to act up when the engine gets to operating temperature.

I actually get quite a few 7.3's towed in for a no start that will fire right up after they have cooled down during the ride on the wrecker. I am not sure of the reason, though.