Clackety Sound From Tu3 Head

[Guest smokinslim]

Having just got my engine going again after some 15 odd months stood, it now has a rather apparent clackety sound that seems to be coming from the head or close by. As the revs go up it quickens but quitens somewhat, its most apparent at idle.

 

My immediate thoughts are either that the rockers, etc have deteriorated whilst its been stood what with the oil having settled etc or the valves are catching the pistons slightly. The timing could be out slightly as i changed the belt/tensioner about a week before it came off the road. Another thought is that perhaps the carb is leaking somewhere and its running overly lean on idle, i do have a sucking/blowing noise to identify still as it was too dark tonight, not sure how plausible this idea is though.

 

From what i've described does anyone have any idea which area i want to be looking at as the probable cause? Or perhaps some sound clips of the various problems that may help me? Any help would be greatly appreciated thanks.

Edited November 4, 2007 by smokinslim

[djinuk 2]

get the valve clearances (tappets checked), also check that you have oil or enough oil in the engine, if you have a sucking noise its probably a air leak. grab some easy start or similar and spray it around the inlet and pipes leading to the carb, if you hear the revs rise then u have found your leak. Hope you sort it fella

[Guest smokinslim]

Oils ok, i drained the old (used for a month only!) stuff out and filled it with new before i even tried to start it. I even removed the rocker cover for the fill up to make certain that the rockers, bearings, etc were thoroughly coated with oil before use.

 

Are the valve clearences likely to have changed through lack of use?

 

Next chance i get in daylight i'll be examining all the hoses and replacing where neccessary.

[Guest smokinslim]

Haven't had a chance to check hoses yet, perhaps tomoz weather permitting.

 

Off to read up on all the bits im gonna end up pullin apart to figure this out...

[Guest smokinslim]

Right, just spent the past couple of hours on it.

 

There are no air leaks anywhere so thats one less thing to worry about.

 

I've checked and adjusted the valve clearances, should be fine but if all else fails i'll check this again as its the first time i've done it, not that there's much to it. The noise may have changed slightly since but not a great deal.

 

Next thing is to check the timing from scratch, and check my dizzy is working as intended.

 

As before any ideas will be gratefully recieved, thanx.

[Guest smokinslim]

Cam timing is fine, ignition timing doesn't have any affect on the noise...

 

Could the piston/lining condition have deteriorated drastically while the car was stood outside for so long?

 

Really hoping this problem is in the head so i cant sort it witout having to pull the whole damn thing apart...

[Guest smokinslim]

Still looking for ideas on this if anyone has any thanx...

[Grahamrally 0]

What's been changed since you last had it running 15 months ago? Did it not exhibit the noise before, or was it just less apparent?

If it's a metalic tapping sound coming for the top of the engine then you'd have to assume valve train based. The rockers do tend to tap on TU engines which have a lot of miles.

 

Graham

[Guest smokinslim]

Since its been off the road the rear beam and brakes have been changed. Oh a battery and 2 vacuum hoses in the bay. They weren't in bad condition but i'd got some newer smarter pipe.

 

The cars pushing 200k now, and was starting to sound a little tappy. But not like this. Having looked more closely at them all, the valve springs seem pretty solid and intact, clearances are good, rockers are steady on the shaft there's no sideways movement.

 

I'm starting to wonder if when i first changed the belt and it was a notch out on the cam pulley whether one or more of the valves got bent slighty.

 

I'm awaiting a stethoscope in the post at the min and prob getting a compression tester shortly so i can continue to investigate, narrow down and hopefully pinpoint the problem.

Edited November 15, 2007 by smokinslim

[Guest smokinslim]

The stethoscope turned up the other day so out i went to have a listen. All the inlet ports sound pretty much the same, slight differences between some ports but none obviously stood out from the rest. The same goes for the exhaust ports.

 

Comp. testers now on order so will see what that has to tell me later in the week. So far im still none the wiser really as to what the problem is.

[Guest smokinslim]

Compression tester arrived this morning, first part of the test is now done. Results as follows:

 

cyl. 1 = 90psi, cyl. 2 = 93psi, cyl. 3 = 89psi, cyl. 4 = 79psi.

 

Having read PumaRacing's page about compression testing (they suggest pressure should be 17-20 times the comp. ratio. 17-20 x 9.3 = 158-186psi) these figures all seem very low. I'm still learning about all this stuff as i go along, what do you guys think?

 

Cylinders 3 + 4 seemed to reach pressure quicker than 1 did, 2 was somewhere in between 1 and 3 + 4.

Gonna get a pipette on my way through town today so i can do a leak down test when im home next.

 

The lower pressure in 4 could be the head gasket on its way out as i have the usual oil leak in the front corner that end, slowly getting worse. I've been putting off seeing to it while i get other things sorted. If the head ends up coming off ill replace all the gaskets as a matter of course anyway though.

Edited November 21, 2007 by smokinslim

[RossD 44]

Compression tester arrived this morning, first part of the test is now done. Results as follows:

 

cyl. 1 = 90psi, cyl. 2 = 93psi, cyl. 3 = 89psi, cyl. 4 = 79psi.

 

Having read PumaRacing's page about compression testing (they suggest pressure should be 17-20 times the comp. ratio. 17-20 x 9.3 = 158-186psi) these figures all seem very low. I'm still learning about all this stuff as i go along, what do you guys think?

 

Did you test with the accelerator right down, ie full throttle? Results will be low otherwise.

[Guest smokinslim]

Foot right down before i turned the key, not released until i'd stopped cranking.

[trogboy 17]

done with the engine up to working temperature?

[Guest smokinslim]

done with the engine up to working temperature?

 

Yes. I followed the procedure as detailed on this page written by PumaRacing: Clicky!

[Guest smokinslim]

Done the leak down test this afternoon, results as follows:

 

cyl. 1 = 107psi, cyl. 2 = 104psi, cyl. 3 = 117psi, cyl. 4 = 92psi.

 

Compared to the initial results:

 

cyl. 1 = 90psi, cyl. 2 = 93psi, cyl. 3 = 89psi, cyl. 4 = 79psi.

 

My first impression is it doesn't look too hopeful really Anyone got any heads, blocks or complete engines going spare lol?

[DaveW 6]

i got a block mate, think it was you who asked me on ebay.....

[Guest smokinslim]

...twas yeah. It's a shame you don't know more about the condition of it, ur not too far away from me.

[DaveW 6]

your welcome to come have a look at it, plus i also know where theres a ax gt in a scrappy..