question Big End ?

[thedawnpatrol]

Hi Guys

Firstly Happy New Year to you all.

 

Whilst driving my GPW on our MVT New Year road run, I noticed a metalic nocking noise comming from under my hood, but only when engine was pulling or under load, I have not noticed a drop in oil pressure nor any on the floor.

Could this be the start of big end trouble? what else should I look for, before I drop the sump ? and will I be able to see/feel anything if I do ?

 

Looking forward to an oily weekend!

 

Jules

[Bodger Baz]

Does not sound like big end as they usually rumble when not under load to begin with and generally a drop in pressure is noticeable, especially when hot. Big ends will also rumble/rattle when you first start the engine from cold then quiet down as the oil pressure builds up.

 

is it a high pitch sound? could be a valve adjuster undoing itself (not uncommon) this will give a high pitch tap/tick but usually noticeable all the time.

 

is it a "pinking" sound? from pre ignition. this will only happen under load.

 

Baz

[Blackpowder44]

Find yourself a fairly long screwdriver, with wooden handle if possible. Start up the engine and put the end of screwdriver to the sump, valve cover and anywhere else you choose and put the handle to your ear and the sound will be magnified and you should be able to trace where the knocking is coming from. A method well tried to tune twin SU carbs also. John.

[Richard Farrant]

Jules,

Check to see if the crankshaft nut holding the pulley on, is tight. Might seem odd but it clamps up the timing sprocket and it is not unknown to find this, the same happened with Land Rover 2 1/4 litre engines.

 

Also check timing is not advanced.

[thedawnpatrol]

Thanks for your suggestions chaps, Yes, I will try the screwdriver trick, & yes, at first I thought it sounded like a 'pinking' sound, but what would cause that?

Doubt I will get to it before the weekend, but will keep you all posted!

Jules

[Rick W]

Pinking could be down to something simple like dizzy out of adjustment, points? Sounds like a timing problem though, agreed. Check dizzy first, its easier. Have you got a Jolley EI kit fitted, I know you dont like them but its troublefree and easy to fit.

[thedawnpatrol]

Well, just spent 2 hours out in the cold, trying to get to the bottom of my problem.

Now, she wont start! turns over fast, starter kicks out, fires once but then nothing!

 

Just wondering if.......................................this has all started since I fitted a new 6 volt battery, when first fitted I was supprized how quickly it span the engine, it seamed too fast for it to catch!, anyway it did on several occasions, until tonight, do you think it might be something to do with the dizzy, have checked that, it's not turned in its self, as still tight, have changed condenser too tonight, but still nothing, could it be the ballance weights?

Off to get my Manual out!

 

jules

[Rick W]

Sounds like a definite dizzy problem. My next move would be to take the dizzy out and check for wear or anything broken on the internal engine side. I know you dont like to Jules, but maybe the Electronic ignition may a route to problem solving?

[Bodger Baz]

change points and condensor, then set the timing (making sure you do it on the correct side of the cam depending which engine you have i.e chain or gear as they turn in different directions), i then advance the timing as far as poss before pinking occurs, copes better with modern fuel.

 

if its turning over too fast is it low on compression? i.e valve adjusters have wound out, they do it for fun!.

 

i have electronic ignition on all my stuff, no complaints at all, i source coils from local motorfactors as they are cheaper!

 

Baz

Edited January 5, 2010 by Bodger Baz

[rippo]

its troublefree and easy to fit.

 

I'm not so sure about that, i've had a few problems since fitting one to the bedford, two coils, two caps and a rotor arm.

[thedawnpatrol]

if its turning over too fast is it low on compression? i.e valve adjusters have wound out, they do it for fun!.

 

 

Baz, thats interesting and perhaps where I should be looking, from the start I thought I heard a metalic knocking from the top/side of the engine? but would that only 'knock' when under compression ?

Also why it won't start now?

jules

[Rick W]

Sticky valve?

[Richard Farrant]

if its turning over too fast is it low on compression? i.e valve adjusters have wound out, they do it for fun!.

 

 

Baz, thats interesting and perhaps where I should be looking, from the start I thought I heard a metalic knocking from the top/side of the engine? but would that only 'knock' when under compression ?

Also why it won't start now?

jules

 

 

Jules,

 

Do a compression check, it will not take a few minutes and at least you can ascertain if it is loosing compression, for instance a head gasket blown between cylinders.

[thedawnpatrol]

Just cos I know you all love a good problem to solve!

Well yesterday, whilst enjoying a day of work, 'cos I could not get there' I thought I would tackle my Jeep.

Well again, she turns over & fires enough to kick the starter out, but thats it.

So I took off the valve cover, then thought it would be easer to see if i removed the Carb and manifolds, carb was easy, but the two nuts under the manifold are right ########!

So, in having removed the carb, I noticed looking into the inlet manifold it was awash with fuel, I had to push in some rolled up paper towl to soak it all up, quite a bit!

I then took out each plug and sprayed penitrating oil in the ports, Then put the carb back and fired her up again...............this time with success! she ran, not as normal, ticked over fine but was a little hessident when revving.

So.................I thought thats it a sticking valve,

But this morning, back to square one! would not start, which anoyed me as I wanted to play with it in the snow!

So tonights job is to take off the cylinder head, turn over the engine and watch which valves stick .

 

will keep you all infomed

 

 

 

Jules

[Richard Farrant]

Just cos I know you all love a good problem to solve!

Well yesterday, whilst enjoying a day of work, 'cos I could not get there' I thought I would tackle my Jeep.

Well again, she turns over & fires enough to kick the starter out, but thats it.

So I took off the valve cover, then thought it would be easer to see if i removed the Carb and manifolds, carb was easy, but the two nuts under the manifold are right ########!

So, in having removed the carb, I noticed looking into the inlet manifold it was awash with fuel, I had to push in some rolled up paper towl to soak it all up, quite a bit!

I then took out each plug and sprayed penitrating oil in the ports, Then put the carb back and fired her up again...............this time with success! she ran, not as normal, ticked over fine but was a little hessident when revving.

So.................I thought thats it a sticking valve,

But this morning, back to square one! would not start, which anoyed me as I wanted to play with it in the snow!

So tonights job is to take off the cylinder head, turn over the engine and watch which valves stick .

 

will keep you all infomed

 

 

Jules,

 

Perhaps the carb is flooding, before doing anything major, remove the carb again and see if the manifold is awash with petrol again.

[Bodger Baz]

The manifold will flood with just a couple of pumps of the throttle due to the accelerator pump, it pumps in lots of fuel each time you press the throttle and if the engine is not up and running at it will pool in the manifold as it has nowhere to go.

 

have you checked the timing? if it too far advanced it will try and fire but kick back and disengaged the starter. even more fun of you use the starting handle! keep your thumb out the way.

 

if you have checked it, its time to do a compression test.