Head won't move, crank spins. (theories welcome)

[diablos991]

I was diagnosing a no-start this past weekend when I realized my cams don't turn while cranking, yet my crankshaft spins because my accessory belts spin while cranking. I was able to remove the upper timing belt cover to find that the belt still has tension and shows no signs of wear.

The only logic that I can work out of this is that my oil pump seized and caused the crank pulley to tear the teeth off where it lies enabling it to rotate freely.

Either that or I have something jammed in the valve train that is not enabling the cams to spin, however, the crankshaft still spins.

The good news is that this happened upon startup (~500 rpms, it started and died immediately) so the damage may be minimal.

Due to time constraints and my lack of a place to work on the Talon, I am forced to take this to a shop. Hence, the reason why I am trying to get an idea what is wrong, both to reduce cost, and to decide if I am going to keep the car or get something else.

Theories on what might be the cause to this problem are welcome. So far the estimated repair bill by Mitsubishi is ~$3k (oil pump replacement, timing belt replacement, possible head work)

 

[assault187]

Im thinking bent valves, check that timing belt again.... For broken or missing teeth

 

[diablos991]

While cranking, the belt doesn't move at all. That is why I am so boggled.

The crank turns while cranking, though it does seem like it is under a fair amount of stress to do so.
If I had the time or place to take the lower timing belt cover off, I would as that would surely show me what the problem may be.

Also while the crank is moving during cranking, there is no audible noise as if a piston was running into valves. The only noise is the sound of a brand new starter trying it's heart out to turn that crank.

 

[Talonracn50]

I bet you bent the valves from the t-belt slipping, and then when you tried to restart it, it stripped the teeth on the timing belt at the crank because there was piston to valve contact and something had to give.

 

[fwdeclipse]

Whatever you do dont take it to the dealer. They will rape you. I am not that familiar with any mechanics around here cause I have always done my own work but dont take it to the dealer. I bet someone on utdsm could help you out.

 

[ThingyNess]

What's very common, especially on cars that have suffered a timing belt job by a novice or lazy mechanic, is that the bolt on the end of the crank snout that holds the crank sprocket on doesn't get torqued down properly. The crank sprocket comes loose and for a while, the woodruff key takes all the load and nothing happens -- until the key shears off and the crank sprocket freewheels. I've seen it happen on multiple vehicles before, although not on a DSM yet.

I'd yank the crank bolt off and take a look.

 

[diablos991]

What's very common, especially on cars that have suffered a timing belt job by a novice or lazy mechanic, is that the bolt on the end of the crank snout that holds the crank sprocket on doesn't get torqued down properly. The crank sprocket comes loose and for a while, the woodruff key takes all the load and nothing happens -- until the key shears off and the crank sprocket freewheels. I've seen it happen on multiple vehicles before, although not on a DSM yet.

I'd yank the crank bolt off and take a look.

That is an interesting theory, this woodruff key has been mentioned to me by a friend.
However, if the crankshaft sprocket was able to freely spin, then how could the accessory belts move when the engine is cranking since the dampener is bolted directly to the sprocket?

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[TimG]

Theory this... theory that. Take the lower cover off.

 

[TurboAnything]

Take the cover off the teeth are stripped off the belt dont try to disprove it we are correct.

 

[Defiant]

The crank sprocket bit off the teeth engaged to it. Your oil pump's fine. You have eight bent valves.

 

[diablos991]

Theory this... theory that. Take the lower cover off.

Take the cover off the teeth are stripped off the belt dont try to disprove it we are correct.

I think you misunderstood the nature of this post.
As stated, I don't have the time or the space to remove the timing belt cover at the present time.
The basis of this post is cost analysis and my main objective is to utilize other DSMer's experiences/knowledge so that I could come up with an idea as to the cost in which I am facing when I take the car into the shop.

I have to decide if the opportunity cost of keeping my Talon outweighs the marginal benefit I would receive from repairing my car.

As of right now, it seems most believe that the problem lies within the timing/valvetrain.

Thanks again to those of you willing to contribute.

 

[ThingyNess]

I missed the part where the accessories were still working. In that case yes, I'd agree with Defiant in the others, in that you sheared the teeth off the belt down near the crank sprocket area.

 

[TimG]

Rebuild the head with at least 8 new valves, new headgasket, new timing belt, new timing belt accessories, new waterpump. Call around for pricing on these parts and labor. Parts alone will be far over $600.

 

[TSITuner4Lyfe69]

haha this guy is well funny either way bro your belt is toast and you need to rebuild your head and replace the head and check the top of your pistons if you dont have time to do it find a fellow dsm'er around where you live who is mechanically inclined and have them fix it and you buy the parts and maybe give him something in return for the work he did if your so "BUSY"

 

[diablos991]

haha this guy is well funny either way bro your belt is toast and you need to rebuild your head and replace the head and check the top of your pistons if you dont have time to do it find a fellow dsm'er around where you live who is mechanically inclined and have them fix it and you buy the parts and maybe give him something in return for the work he did if your so "BUSY"

The sarcasm is much appreciated.
I have changed my own timing belt on a DSM twice. My resources are low due to winter coming in full force and me not having a covered/heated area to safely work on the components that require attention; additionally my upper division courses eating at most of my free time.

I know that all the timing components must be replaced, that is a given due to the nature of the problem. I was most curious about other possibilities that might indicate a block rebuild is needed. If that were the case then the car will most likely be sold. Again, as mentioned in my first post, I have already priced a head rebuild as well as a full timing belt component replacement.

From the feedback I have had so far, I would assume that the chances of needing a rebuild block are moderate at best. So I think I am going to go ahead and turn the car over to Mitsu and brace myself for the bill.

Thanks to those who helped instead of providing their criticism.

 

[blcknspo0ln]

I understand your urgency and lack of resource, but why go to the dealer for this? I have an odd fealing Mitsubishi probably won't even looking at your car, being that it's an "eagle".

If you have done a timing belt change, swapping a head out realistically isn't that much harder, it's just more stuff to remove/replace. IMO, just buy a used 2g head with good valves, swap it on with a new head gasket and arp hardware (don't reuse your 7bolt bolts, and new oem ones are more expensive than ARP). If you have the patience to look, you can have your car running for less than $300. If need be, I have PLENTY of moderately/barely used idler and tensioner pulleys for both 1g and 2g that I will donate to your cause (pay shipping).

 

[diablos991]

Thanks for the offer Tom. I already cleared it with the Mitsubishi dealer, and they said that they would work on it.

I do have one alternative shop to look at though in regards to saving some money.

The main issue here is that this car is my DD and it can't be out of commission for much longer, also I don't want to pay all this money just to have some dingus mess up and not torque something properly causing me even more headache. The turnover at Mitsu isn't really that bad in my area and they do warranty their work better then most shops in my area that I know about.

 

[TimG]

I've replaced a head outside in 2 feet of snow before. Was it fun? Nope. Was it done right? Yup. Would I ever do it again? Nope. Would I suggest you try it? If you are brave.

 

[Big Woo]

Based on your description I would say that several of the timing belt teeth sheared away from the timing belt backing, and right now that portion of the timing belt is positioned around your crankshaft sproket. thereby allowing the crank to spin and drive accessory belts, but providing no rotation the the cam gears, oil pump, and balance shafts if present.

I have seem many DSM's come into my garage with the tim ing belt intact, but missing teeth in spots.

 

[diablos991]

Well, the problem was a faulty oil pump seal which caused some oil to spill on the belt and the crank sprocket to jump and the pistons finally caught those pesky valves. Since this happened upon startup, the top portion of the timing belt in which I was able to inspect was not saturated in oil. However, the lower half of that belt got a fair amount on it.
I replaced all the seals last timing belt job, so it was either my neglect in installation or a bad part.

Either way, I am getting my head rebuild, balance shaft removal, all new timing components, and a pesky dent removed from my oil pan for about $600-$800 parts and labor.

The Talon will most likely be back on the road in the next couple of weeks.