I'm sure I know but ......Getting car ready for spring I was setting the timing on my car with timing light I made the stupid mistake while setting it static , I turned the engine crank backwards a few degrees to line up the pulley timing marks. Something made a loud clicking noise ?? (Thinking chain tensioner?) and when I turned the key to start it made a loud squealing noise .i haven't been able to pinpoint exactly where the noise is from but it's loud . Stopped cranking immediately. Now what? . Just need a second opinion before I tear it down ? Any help greatly appreciated. Tia.

 

Never turn an engine backwards... Never ever ever ever...

 

H
Thanks for your fantastic advice . That'll go a long way towards helping. Do me a favor

 

I don't know. But I've heard from those who do that turning the engine backwards can break the chain tensioner.

I also don't know what has to come off to replace that part. I suspect it doesn't require pulling the engine, but that pulling it would be the option many would choose.

Others who've been down that road will chime in I'm sure.

Best of luck straightening out this kink!

 

I would turn engine forward and listen, it is very possible that nothing is broken and squealing (as well as clicking) could have came from a slipping belt.

Not being an expert in big car engines, but I have been turning engines backward more than 'few degrees' on my bikes and it never did any damage.

 

The V12 has a bad habit of breaking the timing chain tensioner if the engine is turned backwards, I learned this the expensive way.

It's a bugger to replace and I'm not sure if it's possible with the engine in the car. My engine was a spare so not in the car yet.

 

Thanks that's what I was thinkin happened. I'm pretty sure the tensioner was badly worn before now and came apart when I backed it up . I appreciate your help

 

Guys, enough's enough, right? This is a happy forum, unlike many, let's keep it happy. We all make posts from time to time that are meant to be humourous but which unintentionally annoy another member. It happened to you in reverse Daim, with Steve, remember? Al was looking for help, and he was not to know your brand of humour Daim.


And Al, Daim is a decent sort, give him another chance, what's to lose?
Greg

 

As you can tell, Greg, his answer to you was everything else than polite and you didn't even state anything wrong...

I would have no worry signing a "peace treaty" but I doubt that would do anything useful...

My opinion would be:

 

Apart from the rudeness on this thread ...
l learnt something l didn't know about turning an engine backwards. Is this every engine or just Jag ?

 

Every 4 stroke engine with a connection requiring tensioning.

So a sproket driven engine can be turned backwards. Otherwise all 4 strokes should only ever be turned forwards (or in firing direction, as a few engines run backwards). Two strokes (petrol) and wankels are of course exempt as they don't have valves... Some two stroke diesels can also be turned backwards.

 

OH BOY.......l must have been lucky then. I'm sure l turned my Stag engine backwards a bit when l set up the timing. Eeeeks

 

Daim, right on... No one without ANY sense of humor should ever, ever, ever drive a Jag !
Ken

 

Two strokes have been known to actually run in reverse with the wrong timing setup.

 

The "Messerschmidt Kabinenroller" didn't have a reverse gear. Instead you would run it backwards. A Lanz Bulldog (Tractor) could be started wrong resulting in 2 forward gears and 4 reverse gears

 

Seems like fun in spades.


1. In the middle of the last century, school chum, Roy, had a more than neat
stripped down Model A Ford. Whoops, engine ran fine, but when placed in gear, awful noises erupted and it would not move. Teen diagnosis. Busted rear end gears. Pulled it out, split it. Oh, aw...., merely a slipped axle key. Got another. Put it back together, and in the car. Well within the strength and energy of the both of us. D... , fired it up, put it in reverse and let the clutch out !!! What the ..... it lunged forward an durn near took out the back wall of the garage!! Much teen perplexion!!! Roy, a real genius, got it. Redo it. Put the ring gear on the other side of the pinion. Done,
Even teen energy exhausted. But, yipppeee, all was well.


2. Another similar, decades later, this time with another pal. A VW with same issue. Same fix.


3. Corvair CCW engines adapted to VW transaxles. Same fix.


Carl

 

When seeking free advice...

...it seems unwise to either complain about how much it costs or in what manner it's delivered.

That said, you've got to feel bad for the guy, and I imagine that his anger isn't really at Daim. He's got that pit in his stomach that he really screwed the pooch*, and he's in the lashing out stage of grief.

*we've all been there and know that feeling.

At the risk of him telling me to go **** myself, the advise I would give him is to take a deep breath, go for a walk, and when he's ready to tackle the problem -- come back and apologize to everyone. If he did, he would find many people eager to help bail him out.

When you find yourself in hole, stop digging.

Cheers

 

Hi Malc

I didn't know that either!

One way or another, someone may have saved me from a Very Costly mistake, as I have a horrible feeling that I would also have turned an Engine backwards, if I had over shot the TDC.

 

Well said.

 

I am curious to know if anything in fact broke.

To set timing and valve clearances one has to turn engine forward to have all 'plays' and 'chain sags' in the same position they would be when engine is running. While turning engine back seem like something we never (or rarely) do, I have issue accepting that turning engine back few degrees will "likely" break something. I think it is actually "unlikely".