Timing belt slippage?

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2001 Mazda Protege ES 2.0
My car started to run not so great. I kept it limping along and when I tried to push it to cross the street the car shut down and will not restart but cranks very easy. Took it to a mechanic who said the timing belt isnt broken but when it cranks pressure comes out the intake. Also gives a message the the cam timing sensor (one in the valve cover) is bad. I tend to think it jumped several teeth. I havent done anything with it cause in south florida it is like a 110 degree sponge out there. The mechanic wanted to replace the whole motor. Just let go from my last job and I cant afford that. Any ideas? I feel running a compression test is a start. What else?
 
Why does the mechanic think the engine needs replaced? Are you sure the belt slipped? There's no reason to assume. Pull the valve cover and rotate the engine while watching the camshaft lobes. This is what your mechanic should have done...

There is potential for damage to the pistons or valves when the timing belt slips. But it's not a guarantee on this engine. Again, no reason to assume. So like you said, compression is a good first test. If compression is good, then the valves and pistons are probably okay.
 
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Yeah its rare to have valve damage on theae engines. But does happen so better safe then sorry. You can pull the valve cover in 3 minutes. Doing this will tell you a lot about whats going on.
 
He did check and make sure the timing belt turns when the motor is cranked. I think he said to replace the motor for the money. He just did the belt and tensioner 20k ago. I am driving my other car but it gets like 15 mpg. Looks like I will get my hands dirty this weekend.

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He should of checked the time. Did a compression test. And that could of told him everything pretty much. It is much cheaper to put a used engine in rather then dig into it internally. For sure.
 
Did I miss the reason why we aren't paying attention to the CEL? If it says cam position sensor issue and timing belt was replaced 20k ago why wouldn't you start with a cam position sensor? Especially after you say he says the timing belt turned with the crank. How exactly would you do a compression test thinking timing belt issue where valves might not be closed at the right moment or at all? If the cam sensor is toast then how would it know when to make the plugs spark? If it doesn't know when to spark then it isn't going to run. Sure, the mechanic wants to replace the motor, it's what they do. They are all about making money, not saving you any. Let's replace the motor because it has a bad sensor CEL and no obvious physical issue.......that sounds about right. I would start with the sensor. 1 bolt, 1 plug, easy access & much less than replacing the motor time and moneywise. Get someone with an ohmmeter and check the sensor before even buying that.
 
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I was assumming the CEL is from mayne when the dude had valve cover off and cranked the engine with the cam sensor unplugged. Lol
 
Valve cover hasn't been pulled. I will do a compression test this weekend. So damn hot I don't want to do this in my parking lot in Florida summer

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Want to make sure there is no physical damage to the valve train as long as that she good I can look further. It sounds untimed however

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Did I miss the reason why we aren't paying attention to the CEL? If it says cam position sensor issue and timing belt was replaced 20k ago why wouldn't you start with a cam position sensor? Especially after you say he says the timing belt turned with the crank. How exactly would you do a compression test thinking timing belt issue where valves might not be closed at the right moment or at all? If the cam sensor is toast then how would it know when to make the plugs spark? If it doesn't know when to spark then it isn't going to run. Sure, the mechanic wants to replace the motor, it's what they do. They are all about making money, not saving you any. Let's replace the motor because it has a bad sensor CEL and no obvious physical issue.......that sounds about right. I would start with the sensor. 1 bolt, 1 plug, easy access & much less than replacing the motor time and moneywise. Get someone with an ohmmeter and check the sensor before even buying that.

The OP didn't mention the specific code, but I assumed it's probably a P0016 CKP CPS Correlation code, which usually stems from a timing belt failure of some sort. Sometimes a P0340 or similar will be set as well.

Not sure about the P5, but a lot of cars will run just fine without the CPS.

A good mechanic can tell an engine with a busted timing belt just by listening to the engine crank. Usually all but one or two cylinders will have no compression, it makes for a very uneven rhythm.
 
... I assumed it's probably a P0016 CKP CPS Correlation code,..

Not sure about the P5, but a lot of cars will run just fine without the CPS.

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We don't have that code for our car. (because its old and has a dumbly ECU that runs windows 95)

I know if our car gets no signal from either the crank or cam position sensor (I forget which one) you will get no spark (the ECU kills the spark)
 
You need a new mechanic.

Why does it seem that mechanics have no ability to do diagnostics these days. It's much easier (ie more profitable) to blame some random part, bill the customer for it, and then say, "oh gosh, golly gee, that didn't fix the problem. Let's throw this other $$$$part$$$$ at it."

Diagnosing a timing belt through the oil fill? Seriously??? Pathetic.

You can diagnose an engine out of time from the sound of it cranking, but you can't diagnose that the whole engine needs replaced.
 
You need a new mechanic.

Why does it seem that mechanics have no ability to do diagnostics these days. It's much easier (ie more profitable) to blame some random part, bill the customer for it, and then say, "oh gosh, golly gee, that didn't fix the problem. Let's throw this other $$$$part$$$$ at it."

Diagnosing a timing belt through the oil fill? Seriously??? Pathetic.

You can diagnose an engine out of time from the sound of it cranking, but you can't diagnose that the whole engine needs replaced.

You can see the end of the exhaust cam through the oil fill cap. You can't see if the timing is correct, but it's an easy way to see if the belt is broken altogether.

The majority of Japanese 4 cylinders are scrap metal when the timing belt fails. The labor and cost of installing a complete head assembly usually exceeds the cost of a used engine. I wouldn't consider it all that unusual for a mechanic to assume the same for a P5, which can be interference or non interference, depending on who you ask.

It's easy to discredit a mechanic when you only have one side of the story that is vague at best.

OP, cam timing needs to be verified before you go further with a compression test. Like I and others said earlier, rotate the crank pulley to TDC on the timing cover, then pull the valve cover and look at the cam timing marks.
 
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Alright alright there are two really easy ways to verify if the timing belt has indeed slipped. Method 1: pull the timing cover and check to see if the marks on the cams and crank line up. The best way to check is to jack the car up and rotate the crank two full rotations. If one or both of the cam marks don't line up with the associated marks on the block, the timing belt has slipped. Method 2: buy or rent a compression tester (renting one in Autozone is like $10.) Remove the spark plug and hook up the tester to the spark plug well and turn the engine over AFTER disabling the fuel injectors. Repeat for each cylinder individually. If you get extremely low compression in all cylinders, the timing belt has slipped.

My guess is that mechanic is just trying to extort money from you. Despite what mechanics want to claim, the FSDE's are non-interference engines and chances are, if your timing belt slipped, you wouldn't need to rebuild the top-end. All you really need to do is replace the timing belt, tensioner and pulleys and for my MSP, that cost me about $250 and a weekend of labor. Btw, in my case, the timing belt actually snapped while I was doing 45 mph and yet after I did the timing belt replacement, my car runs like nothing happened.
 
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Well these engines are non interference so if belt goes 80% chance nothing was damaged. Hope you get it all figured out!! It is always a pain in the butt when something goes wrong with our cars :(
 
You can see the end of the exhaust cam through the oil fill cap. You can't see if the timing is correct, but it's an easy way to see if the belt is broken altogether.

The majority of Japanese 4 cylinders are scrap metal when the timing belt fails. The labor and cost of installing a complete head assembly usually exceeds the cost of a used engine. I wouldn't consider it all that unusual for a mechanic to assume the same for a P5, which can be interference or non interference, depending on who you ask.

It's easy to discredit a mechanic when you only have one side of the story that is vague at best.


OP, cam timing needs to be verified before you go further with a compression test. Like I and others said earlier, rotate the crank pulley to TDC on the timing cover, then pull the valve cover and look at the cam timing marks.

Wait a minute. You say you disagree with what I stated...and then proceed to reiterate what I stated?

We already know the timing belt is not entirely broken. Diagnosing it any further through the oil fill can't be done.

This is a none interference engine. Some people get valve to piston contact, many people do not. Suggesting the entire engine needs replaced after only removing the oil cap is absurd.

Further, nobody has commented on the fact that this mechanic replaced the belt 20k miles ago! Something is wrong if this engine has already jumped time.
 
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