Top end tappety type noise

Top end tappety type noise

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blaze_away

Original Poster:

1,520 posts

215 months

Tuesday 4th June 2019
quotequote all
OK back to some basics.....

I have set the engine to TDC No1 cylinder using bodgers method ie long screw driver in No1 spark plug hole rotate engine back and forth till TDC obtained......check timing marks on pulley.

and behold they are miles off.
Whites marks on pulley are at TDC, 6 Degrees adv and 12 Degrees adv



New tdc marked on pulley and will now put plugs back in and reset distributor timing

is 8 degrees at idle and 28 at 3000rpm right ?

blaze_away

Original Poster:

1,520 posts

215 months

Tuesday 4th June 2019
quotequote all
Steve_D said:
You need to be really sure about true TDC.
I use a dead stop which is a modified spark plug with a length of M8 bolt out the end.
A selection for different engines.


Screw it into No.1 and carefully wind the crank round clockwise until the piston comes up to the stop. Mark the pulley at the timing pointer. Wind counter clock until the piston again come to the stop. Mark pulley. TDC is half way between these two points.

Now to your problem which looks to be a broken pulley. The pulley is actually a vibration damper and consists of the inner section which fits on the crank and the outer ring that has the timing marks. They are joined together with rubber in the same way as a factory fit suspension bush.

The rubber bond has broken down and the outer ring has moved. The problem is that the ring has been drilled as part of balancing the engine so the engine is now out of balance. We had one a few years ago and we sent it over to Powers (I think) who measured the balance drillings and drilled a new one to the same.

Steve
WOW.....Now that is interesting.



blaze_away

Original Poster:

1,520 posts

215 months

Tuesday 4th June 2019
quotequote all
Thanks again really appreciate your knowledgeable input.

Been on Rimmers website and looks like there are a number of variants so first need to get my old one off and see what it is.

blaze_away

Original Poster:

1,520 posts

215 months

Wednesday 5th June 2019
quotequote all
Firstly you folks are amazing, always there to help a fellow TVRer in their hour of need. I am indeed in that hour losing the will to carry on at the moment after today. more on that in a moment

Apologies my profile needs updating car is 98 serpentine, the 93 one was my first one.

Will be attacking the bottom pulley as soon as I can find a breaker bar suitable.

Yesterday put it all back together ready for timing set up. All done fine and set at 12 degrees adv on idle. observed it advances more as engine revs increase.

Noticed cylinders 5 & 7 exhausts are completely cold. ie 50 degree when all others are at 250 degrees plus

Checked firing order all good
Swapped ignition leads no change
Checked sparks, same as all other cylinders, not super fat sparks but they are sparking
Swapped plugs no change
listened to injectors with stethoscope all sound the same.
Measured compression on cold engine though both registered 140 psi same as all others
Dismantled top end again to inspect valve lifts all clearly lifting but couldn't measure actual mm of lift as dial gauge was lent out.
Swapped injectors from good cylinders, not that as they performed ok in new locations
reassembled everything and restarted it.
Still not joy, 5 & 7 exhausts still stone cold.

My thoughts.............stumped on this now
Head gasket ?

blaze_away

Original Poster:

1,520 posts

215 months

Wednesday 5th June 2019
quotequote all
Good point Lance.

It was cylinders 4 and 5 where I replaced both rockers

With evidence that valves lift OK on 5/7 I dont know if preload being a bit out would have that much affect. Would guess it would more likely cause long term valve burn. But I am no expert on any of this.

blaze_away

Original Poster:

1,520 posts

215 months

Wednesday 5th June 2019
quotequote all
Good idea but no ditched the extenders years ago in favour of good leads and socks.

blaze_away

Original Poster:

1,520 posts

215 months

Wednesday 5th June 2019
quotequote all
Coil

blaze_away

Original Poster:

1,520 posts

215 months

Wednesday 5th June 2019
quotequote all
QBee said:
That's kiboshed that idea....

Next thought - 5 and 7 are next to each other in the firing order, so must be adjacent in the distributor.
Are they getting enough contact to generate a big enough spark?

if you run the engine for 30 seconds and then switch off and remove numbers 5&7 plugs, are they wet or dry?
I'm on the same page there.

I will take a look in the cap again. Looked OK a couple days ago before reassembly but lets see.

Will do that check for wet plugs

Also will pull the fuel rail & injectors and rig it up with test tube on each injector to confirm and compare quantity of fuel delivered whilst cranking the engine.

At the moment it doesnt add up.
It appears I have fuel, spark at correct time and compression so thats all the fundamentals covered so they should fire but they dont so 1 of those 3 assumptions is false.

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
Good points, the results are in

Is it on flat ?
Yes. Removed and refitted for good measure

Is fuel getting in ?
Yes. Removed king lead cranked for 30 seconds. Removed plugs 2 and 7 both wet with petrol

Off to buy new cap rotor arm ignition module

Anyone know the part numbers drawing a bkank on google.

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
Brilliant fellas and thanks for the offers very kind of you. Will be in touch if necessary, hope I will be able to buy some today

Got part no now
intermotor 44790 cap
intermotor 15410 amp
intermotor 47650 rotor arm

Phoning round local parts co's

Cracking idea on the timing light on 5 & 7

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
Tried timing light on all cylinders

All showing same consistent spark and each was reporting same rpm ie 950 +/- 20 suggesting consistent rates too I guess.

One thing I did discover is that cap was on 180 degrees out, my fault been like it a while maybe 6 months since when I fitted new leads.
Note to self: there is a notch inside the cap that is supposed to locate on a lug on distributor body. It is possible to mount it without that engaged.

Fitted new cap, rotor arm and ignition module and for good measure swapped out the ECU for a spare I have.

Result......computer says no, still no joy 5 & 7 still cold.

I'm completely lost now, the only things I can think of are

1. check preloads although I cant rationalise how that would do this
2. heads off for internal inspection of valve gear and state of pistons and bores

1st time an engine has ever beaten me to this level

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
Steve_D said:
blaze_away said:
............Cracking idea on the timing light on 5 & 7
We also use these as they are simple to use.
https://www.ebay.co.uk/itm/AccuSpark-Sparkplug-HT-...

Steve
Nice one Steve. Ordered

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
QBee said:
....all electrics throughly investigated and/or replaced, plugs 5&7 dry, exhaust manifold at 5&7 still cold.

Suggests no fuel at those cylinders. Either blocked injectors, or injectors not being fired.
Do the injectors fire in pairs, side by side?
On std 14CUX so I believe they are fired in banks ie evens and odds.

I did run a test earlier today King lead off cranked for 30 seconds removed plugs from cylinder 2 and cylinder 7 both were wet with petrol. Not much of a quatitative measure so will remove fuel rail and injectors and crank for a while into test tubes to compare quantities

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
I did check 2 and 7 as I wanted to conpare a reference/control (2) vs a faulty cylinder (7)

blaze_away

Original Poster:

1,520 posts

215 months

Thursday 6th June 2019
quotequote all
QBee said:
...sorry, my misunderstanding.
No problem will be checking 5 tomorrow too. Really appreciate your posts as you can imagine this is driving ever so slightly mad at the moment, it sort of defies logic. It will not beat me (us).

blaze_away

Original Poster:

1,520 posts

215 months

Friday 7th June 2019
quotequote all
Qbee I had my first Volvo in 95 V70 T5 company car my god that wasnt an antique dealers Transit. Well it was it was both a maniac if you wanted it and docile if you had a wsrdrobe to shift. Then had 5 new ones every 2 years after that but 2.4 diesels. Plus wife had 2 civics in same period great cars.

Aĺun D coming over today to throw spanners at it too. Primarily to help get manifolds off so I can change exhaust gaskets to elimate those as source of original problem
No doubt we will also take a look at 5 n 7 problem

And "if this goes on much longer" I might begin considering the merits and methods of self harming as a mild distraction.
If you do feel the urge to bring spanners and spares I would be endebted to you and very grateful. I'm good at tea making !

blaze_away

Original Poster:

1,520 posts

215 months

Friday 7th June 2019
quotequote all
phazed said:
It really does sound like the strangest problem.

Just out of interest, have you swapped some HT leads around so you actually eliminate the leads themselves?
Yep got an identical brand new set of leads so swapped for those still cold.

BUT
Interestingly Alun D came over and by a process of joint observation we both agreed that the spark on plug attached to a lead and earthed initially is quite fat on first crank of the engine then becomes weaker and using an old plug the spark appeared stronger ie Als old bpr6es stronger spark than my 1000 mile old bpr6es.
And oddly No5 appeared to start firing we think difficult to be sure as it was feckin hot in there.

When it stops raining I will
Fit new plugs all round
Refit an old spare set of leads
Buy a new coil and fit that



blaze_away

Original Poster:

1,520 posts

215 months

Friday 7th June 2019
quotequote all
phazed said:
I wonder if you have a set of fake plugs and they are now misbehaving?
Yep agree it was something we discussed. They were bought online from ??? I cant temember.

blaze_away

Original Poster:

1,520 posts

215 months

Sunday 9th June 2019
quotequote all
Well after a couple of days efforts with Alun we've uncovered some significant findings

Bad running cold 5 and 7 cylinders
I unknowingly bought fake BPR6ES plugs !!
Fitted 2 old bc7ecs and now they run not perfectly but maybe the other 6 fake plugs are having an impact too
Will try to source genuine items tomorrow

Tappety noise
Have discovered the main crankshaft front pulley had been fitted with the wrong size woodruff key allowing the pulley to freely move on the shaft. Way to short not tall enough but correct width. No witness marks of any damage at all so with luck will get away with just fitting a new woodruff key.

Getting somewhere now I think.

blaze_away

Original Poster:

1,520 posts

215 months

Sunday 9th June 2019
quotequote all
phazed said:
Just what I thought the spark plugs. I even said to Alan that it is a possibility but highly unlikely to be the Woodruff key, we discussed that on the phone. Amazing that someone would fit the wrong key.
The correct one is amazingly large.
Much appreciated Peter. You and Alun talking offline is a real help. Wasnt looking forward to trying to source a new balance pulley and then having to get it drilled had trouble written all over it.

Will inspect the timing gear and maybe even pull the cam for a look and measure too.