Hi Paul_59

She has very definitely never overheated, as I always watch that gauge like a 'Hawk'

But as the Engine was making some very Loud Strange Noises, I'm fearing the Worst.

 

Hi Doug

Cheers! but right now I'm hating myself.

Especially after reading 'Daim's Dire Warning about turning the Engine backwards' which I didn't even notice I was doing.

The Engine was making a VERY LOUD Banging sort of Detonation Noise while at the same time Sounding like an Anvil being Hit with a Hammer.

So not looking good!

 

Hi Mac

What ever the Hell is wrong with the Engine, I cannot imagine it will be an easy Fix and consequently could be very expensive.

It certainly won't be a 'Walk in the Park' that's for sure.

 

sorry to hear about your car OB. I know you have been working on it a long time and are proud of it, but be proud of yourself for what you have done so far. Like others who commented, don't give, just take a break for a few day or even a week, during that time don't even look at it. Then when your refreshed from time off drinking your favorite beverage, go open the bonnet and see what is going on, not only look under the bonnet, look under the car. all may not be as bad as you think as some have suggested, and just have faith in yourself and confidence to get the XJS back on the road. you came this far and know there is a lot of help/advice here

 

When I thought that 'Cherry Blossom' may have suffered a Catastrophic type of Engine Failure, through the 'Possibility' that I may have accidentally turned the Engine backwards.

When I was (unsuccessfully) trying to Start Her, the Engine was making some very Scary noises.

A sort of 'Crackling Crunchy Noise' like Ice Cubes being Crushed and then a Noise like a Hammer Hitting an Anvil.

If that doesn't freak you out, then maybe nothing will, as the Hammer on the Anvil Noise, had me thinking 'Dropped Valve'

Although I've never heard one, the Hammer on the Anvil 'SEEMED' to fit the description that others have given.

Turning the Engine Backwards, was a Totally Dumb *** thing to do on my part, although on reflection I cannot remember, if I managed to stop myself in time.

As Daim's 'Never Ever do that Warnings were starting to ring in my ears.

Then later when I tried to Start her there was a sort of Chirping 'Tink Tink' noise, which I almost thought I didn't hear.

But the following day when I tried and failed to start her, all hell was breaking loose, with all those Frightening Noises coming from the Engine.

Then on reflection I remembered something EQUALLY STUPID that I'd done, when changing the Brake Fluid.

I was going right though the System including the Low Pressure side, which can be a messy business, with Brake Fluid running everywhere.

So this time I had one of those Hand Held Pressure Sprayers like you use for Watering Plants, at the ready full of Soapy Water to Sluice down any spills.

Then guess what I did!

Just by the Side of the Brake Pump, is an Upturned Electric Plug which is Bundled together with a 'Red Tube Thingy' that is Connected to a Micro Switch.

I have absolutely no idea at all what that Plug does, although I'm sure that someone like Warrjon would know.

But the TOTALLY STUPID dumb *** thing I did do, was to get WATER in it!

Which in XJS Terms is one of the Biggest 7 Deadly Sins!

Never let Water anywhere near the Engine!

So again on reflection, could getting Water in that Socket have caused the Engine not to Start and have it making all those Scary Noises?

Does anybody know?

Here is a Pic of that plug that I got Water in.



I got Water in this Plug, could that be the reason that the Engine wouldn't Start and was making all of those Dropped Valve Sort of Noises?

 

Dry out and clean the socket and corresponding plug first. Then check around the belts and fans to make sure nothing is fouling any moving parts, cross your fingers and try again. You never know.

 

OB that plug is for the ignition diagnostics. Nothing will happen if you floor it with water or so.

 

You need to survey the engine and determine what has happened before you make and assumptions on engine damage.

Check all externals for damage, as was suggested earlier the fan and oil lines etc. If everything is good then pull the valve covers to see if there is any valve damage, turn the engine by hand.

You can rebuild the engine without removing it from the car.

I had the port engine in my boat drop a valve when I started it and it makes a HELL of a racket before it dies that was a 350ci Mercruiser (chevy)

 

Hi Dave

Cheers!

But it was Total Stupidity on my Part and The Jaguar Gods were upset.

 

Hi Jim

Cheers, it might be Worth a shot, I mean apart from everything what else could go possibly wrong.

 

You don't really want an answer to that, do you.

 

Hi Daim

Cheers!

But could you tell me what can happen, if you turn the Engine backwards, or have I just found that out all by myself!

 

Hi Warrjon

It certainly made a racket that's for sure!

 

Sorry to hear that OB...not sure what I would do if faced with the same thing. I know I would not give up my coupe but it may sit there a long long time while I was putting it back on the road and for more dollars than I could justify.

 

Not really, Nooooooooooooooooooooooooooooooooooooo!:icon_deadh orse:

 

Hi Ron

Well at least it might stop someone else from making the Same mistake.

 

OB, if you stand on front of the engine, the crank rotates clockwise. The crankshaft sprocket tugs on the chain coming from the right (B bank camshaft). So, it has tension due to the tug of the crankshaft on that side.

The other side has slack. Hense the use of a tensioner. The chain would otherwise just flap around and possibly jump a tooth or two when reving it.

Now comes the tuning it backwards, aka counter clockwise. So, you turn the crank backwards. This loosens the tension on the B bank camshaft sprocket and builds up tension on the A bank camshaft sprocket. By doing so, you are putting a lot of strain on a part not meant to be strained: the chain tensioner. This just takes the slack of the chain but with out using the retractor tool, it won't retract.

This strain can cause the tensioner, as it is only a plastic guide with a metal spring pushing it, to either fracture, snap or even break the mechanism.

Apart from that, you can lose all the timing, as the chains will, when no tension is applied to the B bank side, jump a tooth or so. So you can by accident put the timing off. Best example is the Wizard of Oz's setup procedure for the Lucas distributor. Always turn the crank a full 720° to align it. Even of you are out by 1° never turn it back as the timing will still be out.

I hope this helps you understand why engines should never be turned backwards.

I'll try and see if I can get my front plate off sometime soon to see if mine is in danger. I don't trust plastic. Especially coming from an XJ8 with Jaguars AJV8 engine. The tensioners on this are originally made of plastic and ALWAYS fail. Mine were just about to as I changed them early 2016.

 

Hi Daim

Cheers!

That's not looking good then, the Chain may have jumped and put the Timing out.

Hence all those Scary Noises, I've been hearing.

Have they upgraded the Tensioner, like I believe the did on the XK8 where I 'think' they replaced it with a stronger one.

Just out of interest, what do you think are the Chances of it Starting and Running OK and if it did would I be living on just borrowed time, up until

something goes bang.

 

OrangeBlossom


Please open bonnet and stand at front and remove the coil wires from distb.
then with out the fear of it starting stand at the front and have some one crank it while you look and listen at the front... you might have part of the fan banging on something!?

 

sounds like good advice, don't assume the worst until you have eliminated simpler causes.

Hope all is able to be rectified, don't underestimate your ability