Mouse in the Gears

[caspereeni]

Hi all. Finally a nice day in RI and I brought the spider out for a ride. 1978 stock engine. It started to backfire and finally stalled. When I went under the hood, a little mouse had unfortunately been caught between the timing belt and a cam gear, causing the cam to be off by about 5 teeth. How screwed am I? I plan on putting on a new belt and checking for compression. Should I bother or just pull the head? Belts are cheap and I'm fairly fast doing one after 15 years of changing them. Also, I have to have a word with my cat who is supposed to keep the mice out of the garage!

[gchocevar]

You are probably worried that the valves might have touched the pistons. I am not sure if 5 degrees would be a problem. You can perform a rough visual through the spark plugs. Solder a small Christmas light to a 1.5 volt battery with about 12 inches of wire. You can drop the light into the spark plug hole and get a pretty good view of what's going on. I am sure someone makes a professional setup like this.

Greg

[caspereeni]

And check the pistons to see if there is any impact marks? A light like that is $10 on Amazon. Good idea! I was also thinking of taking the exhaust manifold off and using a mirror to see if the valves close all the way, using a little inspection mirror. There were no mouse remnants on the intake cam gear so I would think that side would be fine. I'll post what I find. Thanks!

[spider2081]

There are bore scopes that blue tooth to a cell phone available for under $50. You can get a good look inside the cylinders from the spark plug holes with it.
https://www.amazon.com/Depstech-Endosco ... pons&psc=1

[caspereeni]

Thanks for the advice. Very neat little tool. I was able to look up at the valves and down at the pistons. It doesn't look like anything hit anything else. Gonna put it back together, throw out the left over pieces and see what I got. I also found lots of mouse bits all over the engine compartment. RIP Mickey.

[18Fiatsandcounting]

Yes, do have a word with your cat! But seriously, and someone can correct me if I am wrong here, but I didn't think the 1800 cc engine (1978) had an issue with valves hitting the pistons if the cam timing was off (even by a lot). I know the earlier engines will have an issue with valves and pistons trying to be in the same place at the same time when the cam timing is off (ask me how I know...), but not the 1800 engine.

Get a new timing belt, get rid of any mouse "remains", speak to your cat, set the cam timing correctly (including the auxiliary cam), and see how it runs. From there you can do additional troubleshooting if there are issues.

-Bryan

[RRoller123]

Other way around, I am told. The 2L is not an interference engine, unless one puts a large valve head on it, as I have. The 1.8L IS an interference engine.

[18Fiatsandcounting]

Other way around, I am told. The 2L is not an interference engine, unless one puts a large valve head on it, as I have. The 1.8L IS an interference engine.

Good to know, Roller, thanks for correcting me. I have had only one 1800, and I vaguely recall rotating the crankshaft slowly by hand (with the timing belt off) and not finding any issues with pistons touching the valves. Perhaps I was just lucky. My 1438 cc engine did have a high rpm argument between the valves and pistons when the timing belt jumped many teeth, but much to my surprise, a new set of valves and guides fixed the problems. The pistons won that argument, and I still have the bent valves as a reminder...

In any event, with Caspereeni's issue, here's hoping a new belt and correct timing provide the solution. A compression check would be a good verification.

-Bryan

[caspereeni]

All done and it runs. Always a happy thing when doing a belt. Extra happy when valve damage was possible. And spring is here.
I did read that they used 2 different serial numbered engines on the 1978. The earlier one was interference the later was not. It may have been in one of Brad's guides, he has documented so much great info and I'm certainly better off for it. Thanks Brad!