Apparently there is something wrong with this engine from the get-go. This is a 20v Silvertop 4AGE just installed to replace the dead 180,000 mile 16v 4AGTE in my La Bala.

Notice that the new engine sounds good at startup but the noise gets progressively louder.

http://www.youtube.com/watch?v=BK_hqG0d5QE#GU5U2spHI_4

Timing is spot on, valve clearances are within .001, new oil, new filter, no sludge in engine, nothing in the combustion chamber, healthy plugs. The engine was primed and oil pressure brought up with the plugs out before I attempted first start. It started immediately, but also started making these noises almost immediately.

Thanks for playing!


Before I tear the engine down this weekend to replace the bearings I thought I would give you a chance to take a guess as to what you think might be wrong.


So far I have as possible guesses:

1- rod knock
2- spun bearing
2- stuck or bent valve(s)
3- distributor shaft/bearing
4- stuck or faulty vvt timing assy

Have you used the old screwdriver tirck to try and pinpoint the location of the noise?

It's too irregular and "sharp" sounding to be a failed big end bearing IME.

Make sure all cam pulleys are tight, I've heard similar noises from pulleys which have been run loose and worn the keyways.

Could also be a broken valve spring perhaps?

Yeah it crossed my mind that it might be a broken valve spring too.

I would whip the rocker cover off before you go any further and watch it running if it doesnt make too much of a mess.

Have you done compression tests on all cylinders yet?

I know nothing about this 4age engine but even something like very badly adjusted valve clearances could cause that type of noise especially as valves and seats settle after a rebuild.

I wouldnt be rebuilding just yet....

That's not a pleasant noise...

The noise is arrhythmical - it doesn't seem to happen exactly in time with the engine - so something loose would be my first guess. My first thought was the same as Mike's - check that the pulleys are properly tight (it's got that sort of sound about it).

In my limited experience, nasty deep-engine noises tend to be exactly in time with the engine. This sounds like something flapping.

Hi, if this is a low mileage Japanese import job, Raw Engineering (info@raw.uk.com...UK(1432)371169)) import them here and say they can sound like a bag of nails for a while then run smooth. Contact them for advice, but, they say this is not unusual.
Regards
Martin

Compression test will rule out valve problems so that's job number 1.

After that a mechanics stethoscope can be useful to find out where the noise is coming from...

Compression is 150psi on #1 and 120psi on #2,3 and 4 . This seems really low to me.

I have a leakdown tester and will run that test this afternoon.

It is a JDM engine and it'd been sitting in storage since 2003, according to the original purchaser. Bag of nails, yes indeed.

About the arrhythmical nature of the sound. That is the loudest sound. Once I correct that one, I believe there is another sound coming from inside the engine. Yesterday the internal sound was louder, not the top end sound is louder.

Jenkins, Interesting (great) note about the timing pulleys. I did replace the tensioner and maybe I did something wrong... I will have to go through this today. Could a loose belt be the issue? A new belt is on order anyways as I had planned to replace this item.

The timing pulleys/tensioner could explain the knocking noise coming from apparently the bottom area around #1 cylinder and the huge valvtrain noise out by #4?

The noise is so loud that the screwdriver trick doesn't really work too well.

Not an expert, but if it was the bottom end, it would probably still run OK & accelerate (sort of).

If you're having trouble with acceleration then I'd suspect timing issues - i.e. check valves, cam timing etc....

Steve,

It sounds to me like it could be the VVT. I think on these engines its a vane device. Does it need to be primed with oil?

Colin

It does sound very much like mine did,which turned out to be 2 broken valve springs.

Ever the optimist....

I work in a VAG bodyshop and years ago when we were regularly repairing Golf Mk2's, after a long repair, perhaps a month out of use, the hydraulic tappets would drain back and would rattle like a good un.

Nothing would cure this except a damn good thrash of about 6-10 miles - cured it every time. Your engine has been laid up for 5 years!

definitely valve train, but what I don't know!

As others have said, its an irregular noise, bottom end would be like a clock.

I'd also go with the previous comment on followers, but then I don't know the engine at all.

PS I would also avocate the thrash it technique, but don't blame me if it makes it worse!!

On the vauxhall XE engine with drained down followers, the only cure seems to be a lot of revs

not hydraulic lifters tho... SHould I still thrash it?

G.

hmmm, maybe not then!!

I really don't know, but the "coming and going" noise sounds like a follower issue.

maybe it is the vvt as you say?

Stupid guess but is it possible that a nut has dropped into one of the cylinders? - It would stick in the oil on the piston/cyl wall when cold and then shake loose on start up and would sound v. irregular - If it is then your bore may be shagged...

Edit: "...Nothing in the combustion chamber..." - Told you it was a stupid suggestion

[Edited on 28/3/2008 by NeilP]

If it is due to air in the vvt mechanish resulting in backlash than it may clear if the solenoid valve is operated one way then the other, which MAY occur if the vvt solenoid valve is disconnected then reconnected a few times with the engine running.
I would check with othe users of this engine first though to make sure that no problems occur from doing this.
The comments regarding the rattle disappearing after running for a while would tie in with this problem.
Have you had any feedback from the other forums yet?

The vvt issue was brought up by 2 other people. But you are the first to explain it so well. I like it. A lot!

Level one:

I will first try to activate the VVT a bunch of times at different rpms, then try the clutch.
Following that I am removing the distributor and replacing with a universal rubberized plug.

Level 2:

I have also bought a new timing belt and will pull the crank pulley, check the tensioner and replace the belt. I'll also check the exhaust pulley.

I need to check for broken valve springs, but all of my valve clearances were spot on, wouldn't a broken spring show a hecka-large valve to shim clearance?

I will pull the pan and check for metal particles.

Finally I'll pull the head and do the full monty teardown.

Anything else?

quote:

---

Originally posted by sgraber
The vvt issue was brought up by 2 other people. But you are the first to explain it so well. I like it. A lot!

Level one:

I will first try to activate the VVT a bunch of times at different rpms, then try the clutch.
Following that I am removing the distributor and replacing with a universal rubberized plug.

Level 2:

I have also bought a new timing belt and will pull the crank pulley, check the tensioner and replace the belt. I'll also check the exhaust pulley.

I need to check for broken valve springs, but all of my valve clearances were spot on, wouldn't a broken spring show a hecka-large valve to shim clearance?

I will pull the pan and check for metal particles.

Finally I'll pull the head and do the full monty teardown.

Anything else?

---

No diagnosis YET but are there 2 holes in the exhaust manifold?? If so gun gum them up temporarily and then let us hear it again.

Ok, I think I may have a breakthrough!

I went to put the car in gear after engaging the clutch and there is no drive connection whatsoever to the transmission.

Then I tried to spin a half-shaft with the other end locked and the transmission will not spin at all.

All of a sudden I am thinking that it's not a crazy idea to look into the bellhousing to see if something is broken inside of there. That would explain a LOT if the clutch disc is broken or some nonsense like that! The clanking noise being some piece banging off the flywheel.

I have never heard of such a thing though and the engine/transaxle did slip together so nicely when I assembled them...

But if there is no connection between the engine and the transaxle and the transaxle is locked up, there may indeed be something going on in there.

I'll follow up with you tomorrow.

no news yet?

Argh. I crushed my hand between the engine and the frame rail yesterday pm and stopped working for a bit. I will give it another go today.

I did verify that there is nothing wrong with the clutch nor the flywheel. I still don't know why there was no drive between engine and transaxle. Maybe when I put it all back together that will be corrected.

I am flailing atm.

G.

It's not the clutch. It's not the vvt valve.

Have another listen if you care.

http://www.youtube.com/watch?v=USvb1nx8r90

At this point I am pulling the head and the pan. I want to at least figure out what that damn noise is.

Hate to say this - but it does sound more like major bearing wear this time around.

If it were my engine, I'd remove the sump and examine the big ends before I ran it again. I would feel happier, even if they proved to be OK.

Just a thought.

Backlash in the VVT mechanism, not the valve, may show up if the engine is manually turned over with the cam cover off.
Check whether the inlet cam jumps relative to the cam drive when the valve springs try to push the cam forward.

I was involved with variabale valve timing back in the mid 80's and it still sounds to me like cam drive backlash.

I hope you find the culprit soon.

I will do this observation on the vvt gear.

I should be able to hear this 'clack' if I were to remove the valve cover, remove the plugs and crank the engine. It would be the same volume if the cover were on or off right?

One clue from yesterday I forgot to mention -- when I was priming/cranking the engine with the plugs out; from inside the #4 cyl plug hole I kept hearing a strange thwunk as the piston would switch directions up and down. tdc/bdc ... A hollow thwunk - like someone slapping the open end of a glass bottle with their open palm. But it went away after a bit of cranking. The engine started up and ran silent, but only after about 10 seconds the clatter sound came on again and just got louder.

quote:

---

Originally posted by CairB
Just a thought.

Backlash in the VVT mechanism, not the valve, may show up if the engine is manually turned over with the cam cover off.
Check whether the inlet cam jumps relative to the cam drive when the valve springs try to push the cam forward.

I was involved with variabale valve timing back in the mid 80's and it still sounds to me like cam drive backlash.

I hope you find the culprit soon.

---

quote:

---

Originally posted by sgraber

One clue from yesterday I forgot to mention -- when I was priming/cranking the engine with the plugs out; from inside the #4 cyl plug hole I kept hearing a strange thwunk as the piston would switch directions up and down. tdc/bdc ... A hollow thwunk - like someone slapping the open end of a glass bottle with their open palm. But it went away after a bit of cranking.

---

I took the head off and the problem became evident pretty quickly.

First off there is some deep scoring in #4:



Next is the piece of metal welded to the top of the cylinder wall in #3, along with some horrible scoring and piston damage:



But the crowning glory has got to be the fact that when you rotate the crank the #4 piston has about 1/2" of slop before it moves up or down! I took a video but I can't even bring myself to post it up.

Top it off with the almost certain knowledge that the vvt pulley is bad and that there are flecks of aluminum galling off the cam bearings and it's easy to believe that this engine was abused at some point before I got it.

It's almost unbelievable to me that someone would and try to pass this piece of ____ off as a usable engine. I unfortunately left him good feedback on eBay before I tried to start it up. Of course he will claim that he didn't know about this damage... So what can I do but take it like a man and move on?

To me it seems like it's not worth the effort of rebuilding.

Damn it I am pissed as hell right now.

Steve you have my sympathies.

A company local to me sold me parts for an early cross flow when I explicitly told them it was for the later cross flow. When I suffered engine failure as a result they refused to do anything about it because 'I had not given them a written order'


I don't hold grudges


much


oh it was SHELLTUNE of Northampton.

Never used them since.

Not good news

The markings on no.4 suggest to me that it's been sat full of water at some stage.

I sort of know how you feel as I bought my current car from Ebay and advertised as "sometimes smokes a bit". As it was a turbo I figured the seals were on their way out. Turns out "a bit" actually meant "completely obliterates the road behind you", and the cause was a melted piston...

I think you just have to believe that the laws of Karma will eventually catch up with them.

Here's a video of a piston that does not move or play well with others.

http://www.youtube.com/watch?v=lz3zptp-GjM

I will take this and chalk it up to experience.

What I have learned (along this entire car project) is that you should not always try to go for the least expensive solution. I have spent more time trying to fix engines than I have driving the car.

Next engine will be thoroughly checked out and I think I'll go for something with 200bhp! Just to make me feel better.

Sorry to see the damage, at least you can move on now. Whatever the problem it's always better to know.

No 4 does look like it has had water damage.

I once had a bike engine with a broken gudgeon or wrist pin that had similar movement.

What engine are you thinking of using next?

Commiserations,

Colin

Hmm, evidence of water in the bores and what could be a broken piston or gudgeon pin. What are the chances this engine has sucked in water and been hydraulically locked at some time in it's past?

looks that way, hydrauliced engine and snapped pin.

would it be cheaper to get a rebore and over sized pistons instead of replacing the engine with something else.

I'm just thinking of everything else that goes with the engine. G/Box, Loom, Time, Effort???

quote:

---

Originally posted by Mark G
looks that way, hydrauliced engine and snapped pin.

would it be cheaper to get a rebore and over sized pistons instead of replacing the engine with something else.

I'm just thinking of everything else that goes with the engine. G/Box, Loom, Time, Effort???

---

Ah shit! hate to see that happen.

looks like, the headgasket had been blown at some point in it's life and the owner has carried on running the engine afterwards, left it overnight, and started it up the following morning,
I have just fixxed a toyota starlet which has exactly the same problem.
the starting with the cold engine with the cylinder filled up with water has caused hydraulic lock which took the rods and bearings......
eaahuummmmm probably.

the problem with the VVT gear is btw not the valve, but a little backlash in the gears in the camsahft pully, the clatter a tiny bit on idle, almost every vvt engine I have heard does that, the sound is very little.
I have had one Valve failure, it was stuck close so the timing wouldnt advance, making it a very smooth but dull engine but still drivable.

Good luck and don't give up on them, once it's right the 20v is a very nice engine to have.
last years result in the engine demolishing sequence is
6 broken honda's vs 1 broken 4age,
so think again when going the honda route

Grtz Thomas

[Edited on 5/4/08 by thomas4age]

I have to agree about the hydro-lock. It seems very plausible. The head gasket does look almost new. Very shiny, no rust marks or mineral traces, but why would they put a new hg on and leave the bottom end messed up? Were I not going to repair the engine I would have put the old one back on?

looks like they fitted a new gasket to sell the engine off and be done with it perhaps.....
by looking at the orange gasket inserts the engine has never been run with this headgasket.

I have seen a lot of engines being sold good and on first inspection reveling all sorts of isues, my first 20v Silvertop spun a bearing but was neatly replaced under waranty.

grtz Thomas

[Edited on 5/4/08 by thomas4age]

#4 piston and rod on the left, #3 on the right:



There is no bearing material at all left in #4. The bearing surface itself is gouged and pitted. The big end is also bent enough that I can't replace the cap.

In addition, all 4 pistons have cracked ring lands and stuck rings.

The crank at #4 end:



I see a piece of the #4 bearing embedded in the crank, but there are huge divots in the steel surface. In addition, the crank does not spin freely, indicating some other problem on the mains.

I am not going to bother taking it apart further.

The block might be salvaged, but is it even worth it when I can buy another motor with warranty for 500 of your UKP?

I do have one final option. Put the 20v head on top of my 3-rib early 4AGE short block. The pistons and bearings need replacing on that engine, but I understand that it will all fit together. Unfortunately it becomes an interference motor due to the valve flycuts on the pistons not matching.

IIRC the oil returns don't line up on a 3rib and a 20v head. also take note that the 3 rib has an oil pump with much less oompf than a 20v has and most probably needs in order to lube the 4 extra valves and operate the VVT system.
The 20V pistons(42mm main) don't fit the rods in a (40mm) crank 3rib bottom end wristpins are of different desing also. using 16v pistons is most likley to give trouble with interferance.

basicly the awnser is: Don't!
better to rebuild the Gen1 and pay hasselgren to do the headwork...... should yield much more power than a stock 20v-st

looking at the internals and the amount of damage I'd say the engine has been turbocharged in a previous life and has a very bad tune.... the ringlands seem damaged to quite an extend right?

try to get a fresh 20v from japan through a know engine impoter that carries start-up waranty, have a look on ebay there's about 5 at the moment at less then $900,- with waranty offered in the USA.

Other option to do is build a hybrid, 7age 20V with paradise racing pistons or the like....... looking at 180 to a 190 hp in that.

Grtz Thomas

[Edited on 5/4/08 by thomas4age]

[Edited on 5/4/08 by thomas4age]

I did buy a new engine from a reputable reseller on ebay. A blacktop 20v 4age with complete wiring harness and transaxle. It arrived recently and I immediately tore it apart to check it out. It's in fantastic shape and I just can't wait to get it into the car.

Thanks for all the opinions.