View Full Version : eating cam sensors

11-08-2009, 11:46 PM
cam sensor on my black 90 is approx 3 years old
3 weeks ago it went out on my way to work (tach went out)
i had enough time that i drove back home and swapped out cars
autozone was out of stock so i ordered one and for the time being
i swapped cam sensors from my 91 since i had the heads off anyways
well that lasted 2 days then the cam sensor failed again
i figured it was due since that cam sensor AFAIK was the original
well autozone still hadn't got my new cam sensor in so i pulled the
cam sensor from my red 90 well that sensor just failed with only a month of use.

so my question is... what the hell is causing my car to eat cam sensors?

is it just coincidence or am i missing something?

the crank sensor was changed back in february when i rebuilt the engine
i didn't use the cam tool when i set the cam sensor, instead i used the write up. im assuming it has to be correct since my car starts first time everytime and doesn't have any abnormal issues.... could that be causing these problems? perhaps its a tooth or two off??

11-09-2009, 12:48 AM
I would check two things:

Bad/poor/insufficient grounds/ground paths

Are you familiar with the factory grounds, etc.?

What is the maximum voltage at the battery?

11-09-2009, 01:59 AM
what about the synchronizer. I have seen these cars eat cam sensors every year or so as well. The autozone sensors seem to be garbage.

11-09-2009, 02:07 AM
Alan is correct. The cam syncronizer is your problem. The piece that your sensor bolts to....

11-09-2009, 03:11 PM
Explain to me how in the world would the cam synchronizer cause an ELECTRICAL failure in the sensor? The synchro does not touch the cam sensor and is not a part of it's electrical circuit. The only way the synchro would be killing sensors would be if the vane was bent and was scraping against the sensor. But then we're talking about an obvious mechanical failure, which would obviously be easy to spot.

KMT is right, check for bad grounds, loose/dirty connectors (the intermittent connection WILL kill a sensor quickly) or over-voltage.

11-09-2009, 03:27 PM
You are right. The title of this thread is "Eating cam sensors". I assumed mechanical failure. My fault. If this is an electrical issue, then yes you are correct. If this is mechanical, then the synchro is at fault.
Most of the Ford V6's use a syncronizer. On OHV and OHC engine variations. They all have had failures. Especially on the Vulcan 3.0L and the 4.0L OHC engines. I'd be scared to even guess how many I have replaced. That is why when I saw the title, I replied the way I did...
One example....http://www.taurusclub.com/forum/index.php?showtopic=43437
And another.....http://www.explorerforum.com/forums//showthread.php?t=161590
These are only OHV examples. Problems are much more relevent on OHC engines....

11-09-2009, 08:04 PM
well heres a little discovery

when i got off work today i put my new cam sensor in, car would not start with it, tach would not respond

so i put the original sensor in one of my other supercoupes and it starts up fine.

seems as though my synchronizer must have turned slightly, i'll pull it out and check it for any end play or binding when my new synchronizer tool comes in if it is faulty... does anyone know where i can get a new camshaft synchronizer? I'll replace it anyway if its less than $100.

also i was looking at my wiring and the protective loom is gone so the wires are exposed. I'll pull the engine harness and check the resistance across each wire... once I get minimal ohms on each wire i'll replace the looming.

i also added some more grounding as well. I grounded the bellhousing to the battery, block at motor mount to batt, and chassis to batt.

speaking of which, i just ordered the camshaft alignment tool from tooltopia for $22 shipped to my door. The have it listed for $13.60

11-09-2009, 08:16 PM
The synchornizer would have to rotate more than +/-5 degrees before it would be an "issue" for the car. It doesn't have to be 100% accurate.


11-09-2009, 08:22 PM
the more i think about it i really do think it moved on me, now it seems as though the sensor is more parallel with the timing cover rather than slightly pointing out

11-09-2009, 09:02 PM
I have seen the syncronizer bearing fail which cause the whole thing to turn.
I saw that on a 5.0 exploder motor, but that may be the exact same part.

11-10-2009, 12:17 PM
Did you think to check your ignition module?

11-11-2009, 07:40 PM
dis is fine, the car runs PERFECT without the cam sensor plugged in just take a few cranks for it to fire

it actually runs better with the cam unplugged than it used to before it went bad :confused:

Did you think to check your ignition module?

11-14-2009, 11:29 PM
well i am proud to announce that the problem is not the cam sensor

the problem was the dis module... changed her out and she runs beautiful fires up first time every time and pulls much harder now, i even noticed that the revs jump up quicker than before

its a shame the dis module thats bad was only on there since feb of this year less than 5k miles although it did see a lot of track time

btw i would have never suspected the dis module to be the culprit until i started looking up the tach wire to find where it was getting a signal from.

IIRC the tach signal is rendered by the dis module and is located on pin #4.

I might be wrong but i think thats correct, the dis module is on the car and im not about to go out and take a peek but i think thats it.