Could debris in the cooling fan prevent hand turning engine?

wshawn · Post by **wshawn** » Sat Nov 01, 2008 3:24 pm

Could debris in the cooling fan prevent hand turning engine?

As I'm hoping this all my problem is...

Basically I started doing the pushrod seals on my 412 (1.7 W code FI engine) today. I removed the right hand side rockers, removed the pushrods and then the tubes. Cleaned up all the tubes and their corresponding holes in the engine. Reassembled everything on this side (haven't touched the other side yet) and went to turn the engine by hand on the alternator pully to set the valve gaps and could only move it about 120 degrees or so before it got stuck. Reversed the direction and had the same free movement for the same distance.

All four spark plugs are out and the car is out of gear. Not sure if we should have tried this but we even tried to turn the engine with the pushrods removed and again only had the same amount of movement.

Looking inside the cooling fan area we discovered the remnants of old fan belt (a rather large twisted chunk of melted, twisted rubber and string) and spent ages picking out small chunks of belt. Is it possible for other remnants of belt to jam in the fan and prevent the engine turning by hand or is it more likly that we inserted the pushrods wrong and have done something else majorly wrong, like bending a valve or something???

I know (at least I was pretty confident that) we reassembled everything the same as it came off so my choices are-

Firstly, I think, is to remove the fan and eliminate anything jamming there, hopefully it is this. Can this be done with the engine in on a 412 Variant?

Secondly??? I don't know

wildthings · Post by **wildthings** » Sat Nov 01, 2008 8:46 pm

My guess is that you didn't get one of the push rods centered in the lifter and that either the valve spring coils are bottoming out or a valve is hitting a piston.

wshawn · Post by **wshawn** » Sun Nov 02, 2008 12:25 am

OK Could this result in sufficient damage to prevent the engine turning even when the rods are out?

The rods themselves seemed to go in well, should you feel any click or resistance on them to confirm they are in position at the the case end ? And wouldn't the rods have bent instead of a valve?

Trying my hardest here to understand the relationship of all the parts and what could have gone wrong whilst hoping that it is just the last reamins of a dead belt

Post by **doc** » Sun Nov 02, 2008 6:23 am

I think wildthings is right on. T4 pushrods are a little different than T1, in that they sit down in the lifter a little more securely. I had the same issue as you are having when i assembled my first T4. T1 pushrods can just sort of be shoved in. T4 pushrods have to be sort of carefully centered (just a matter of looking to make sure they are fully seated in their lifters).

Try this. Remove the rocker arms and the pushrods. Carefully push the push rods back in their tubes and "feel" that they are all the way bottomed in the lifters. If I recall correctly, you can actually feel where they slide down the last little bit, like they are going over a little ridge. Carefully put the rockers back on, making sure the pushrods don't move off their bottoms. After you're done, slowly roll the engine over by hand. Betcha it'll turn!

Good luck. Report results.

doc

wshawn · Post by **wshawn** » Sun Nov 02, 2008 10:36 am

I'll certainly update you on the results but it will probably be next weekend now as I am having a new kitchen fitted at home amongst other things this week.

I hope you are right.

wshawn · Post by **wshawn** » Sat Nov 08, 2008 9:11 am

Still stumped on this one, had a better look at the fan and there is not enough room to remove it whilst the engine is fitted. Removed as much as I could from around it but could see no other debris. Now unless there is some threads from the old belt behind the pulley/fan wrapping and then unwrapping around the drive for the fan (is it the camshaft?) that I can't see...

Whilst there double checked the valves on the side we did last week and they all look OK as a straight edge placed along the four shows them as all closed as they ALL touch the edge. All the cam followers seem to be moving as well. The rear three on the O/S you can feel and see the push rods move and the front ont one you can just about slip your finger into the pushrod hole and slide the cam follower in and out so I'm guessing that is OK as well.

The rotor arm moves about 180degrees from pointing to the front of the car to pointing at the rear by only rotating to the O/S (number 1 +2). You can only turn the engine backwards and forwards by the same amount.

Now unless I have been incredibly unlucky and for some reason a valve decided to drop on the side we haven't yet touched then I don't know what to do next.

Hopefully my description makes some sense even if the cause of the problem doesn't.

also attempts to rotate the engine by hand with the rockers of meets with the same amount of movement.

412s2 · Post by **412s2** » Sun Nov 09, 2008 3:11 am

Still no luck?

The fan is attached to the crankshaft. It is strange that your engine turned over fine before you did your work on the push-rod tubes and now doesn't. Before you started the work, did it turn over by hand even with the broken bits of belt stuck in there? I would first look to see if I had incorrectly assembled the valve-train assembly as it was only after you had done this work that the fault appeared...

The fact that the rotor arm can spin 180 degrees, does make me wonder if something is sitting in one of the combustion chambers, I remember a few years ago a friend of mine was going to adjust the valve clearances on his 1800cc kombi and he had the same problem. In the end we had to pull the engine and take the heads off as it seemed to be jamming when one of the pistons reached TDC. We found that the accelerator pump injector had fallen out of one of his carburettors and worked its way passed the valves!! Weird!!

Double check your work on the push-rod tubes first, I hope the fault lies there and you don't have to delve deeper!!!

raygreenwood · Post by **raygreenwood** » Sun Nov 09, 2008 10:56 am

The method you are using to check what "we" have been describing with the pushrod issue....will show you nothing at all. The rockers will always return to level at TDC. The valve springs and stems will always move to the closed position.
The rockers cam and lifters are steel. The pushrods are not. The pushrods will bend.

If a pushrod is NOT seated in the lifter cup properly....it will in effect be about 1/2" too long. It will bind up.....but you can only see this and correct for it buy removing the rocker stands and recentering the pushrods.

This is not visible by any means from the outside. YOU MUST REMOVE THE ROCKER SHAFT NUTS TO VERIFY THIS.....

This is worth dropping the engine down far enough to get the fan out so you can verify that you have no threads wrapped around the crank. Ray

Also, are you using the retainer wires for the pushrods?

wildthings · Post by **wildthings** » Sun Nov 09, 2008 5:34 pm

I am wondering if you don't just have some carbon that has sloughed off the top of the piston and is now jambed in the squish area between the head and the piston.

Remove your spark plug and try to blow the offending cylinder clear with an air hose.

Post by **doc** » Sun Nov 09, 2008 6:27 pm

I'm still with Ray. Gotta make sure those pushrods are seated in the cups. It happened to me, juat as you describe. Rocker arms off is an easy job - engine in car. I'd definitely rule it out.

I have seen more than one accelerator pump nozzle get past the valves in my time. Most just beat themselves into the top of the piston, but I've seen one bind a cylinder, just as described above. But that's a remove the engine and pull the heads job. Start with the rockers!!

doc

wshawn · Post by **wshawn** » Mon Nov 10, 2008 12:53 am

doc wrote:I have seen more than one accelerator pump nozzle get past the valves in my time.
doc

Isn't that just on engines with carbs, mines still running the FI?

and if it was an incorrect alignement of a pushrod then removing them completly would alllow the engine to turn, wouldn't it??

I have had them in and out several times and am still no closer to solving this one.

As of yet I have not touched the rockers on the other side although I think I may need to pop the cover and check them out just in case something has happened over there...the frustrating thing the engine was running really well before I started this "easy" job!

I'm also convinced I need to remove the fan, if nothing else just to eliminate that from the list of potential problems.

As for the retaining spring wire that runs into the top of each of the tube I have reinstalled that asd well each time I have reassembled the rocker assembly...

412s2 · Post by **412s2** » Mon Nov 10, 2008 3:12 am

Hi wshawn, yes it definitely wont be a accelerator pump injector preventing your engine from spinning over. I know yours is a D-jet like mine

I really only recounted the story as an example of how something stuck down in the combustion chambers can produce the same symptoms as you have. I ramble on sometimes...

I would have thought that removing the pushrods would have allowed the engine to spin over, assuming nothing else is wrong with the motor! Having only rebuilt one of these engines 13 years ago as a teenager, I am more than willing to be corrected on that!!

raygreenwood · Post by **raygreenwood** » Mon Nov 10, 2008 4:56 am

Wshawn....is your car an automatic or a manual transmission?
Either way...Just remove teh bolts that hold the fan, remove the fan belt first. The nwiggle the fan loose and let it sit where it is .

Then jack te hrear of the car up....put it in gear...like 3rd...and turn one of the rear wheels. This should tell you if something is physically bound up behind the fan. Ray

wshawn · Post by **wshawn** » Mon Nov 10, 2008 5:49 am

The car is a manual Ray.

Unfortunatly, again, I can't get to the till the weekend so will remove the fan and then see what happens

wshawn · Post by **wshawn** » Sat Nov 15, 2008 7:28 am

Got the engine turning over freely by hand now.

Looking through the spark plug hole on cylinder 1 I could see a lump of carbon which was stopping the piston finishing its stroke.

Still need to remove the fan though as my father got a little heavy handed and broke about half a dozen fins on it, tried the old trick of using a large screwdriver to lever it round insisting it'll be OK...after all parents always know better.

Is the fan balanced at all and would this number of damaged fins cause insufficient cooling?