5k Problem Diagnosis

[Davros El Davros]

Hey all..

 

Been a while since I was last on here- been in the process of moving interstate which kills funds and time to work on the rolla.

I am about balls deep into a 4age conversion which has been postponed due to moving from stinktown (aka Wollongong) to Briz Vegas.

 

Got a bit of a problem after driving my 5k powered KE10 from South Coast NSW to Briz Vegas the other night.

 

The engine already had a bit of wear on it, and was starting to chew a bit of oil and blow a small amount of smoke when started.

 

It was also starting to make a light tinny rattle when you reached the top range of each gear before changing to the next gear,

and after the trip up to Brissy, the rattle has got a lot more pronounced and the car loses a bit of power at the upper range of each gear,

where before it would keep revving till you changed.

 

I am figuring its time to throw in new piston rings and check out the valve guides.

 

Just wondering if yall can offer any advice, and also if anyone in the Brisbane area can point me in the direction of a good engine shop.

 

Or would it be better to get my hands on a new 5k head?

 

Any help greatly appreciated. Tried google and the search here, but not many results for what I was after.

 

Thanks

 

DAV-ROS..

[Felix]

You might just need new valve stem seals and a timing chain.

 

Valve stem seals harden over time and don't seal as well as they once did, allowing oil to get sucked down the guides.

 

The 5ks come with single row timing chains standard, which stretch fairly quickly. Single row setups are also prone to fast tensioner wear. Badly worn single row setups eventually get to the point the chain can slap against the inside of the timing cover and wear a groove in it, making a hell of a noise. Note also that when the chains stretch the cam, and dizzy timing get thrown off, hurting performance. A good indicator of a worn timing chain is if you put a timing light on the car at idle and the crank timing mark jumps around.

 

Do a compression check, if it checks out ok (say around 155 psi or higher), then consider fitting new guides and timing chain setup.

 

If you were to do the timing chain, change it to a double row setup... Old 3k's make excellent donor's (for double row gears), as they come with double row setups stock.

Edited January 7, 2008 by Felix

[Davros El Davros]

Thanks Felix - I thought first of all that the timing may be out, but it idles well down low and is fine up until you reach the upper end of each gear.

 

The engine currently has a double row timing chain in it, with gears taken from a 3k that we put in about a year ago. The car hasn't done an excessive amount of miles since then, so

the chain should still be ok.

 

Ill try the compression test for sure - first spare moment Ill head down and get a compression tester and give it a bash then post the results.

 

Pretty logical. Should have thought of this myself. :P

[Felix]

Yea do a compression test.

 

I'd say your timing chain will be fine.

 

Have you done a tune recently? Does it have an electronic or points dizzy? If it has an electronic dizzy timing shouldn't change. If it has points, they tend to close up over time due to rubbing block wear, which advances the timing and can make a motor ping, and lose power.

 

If you were to change the valve stem seals, you can do them without removing the head, using an over head valve spring compressor and some rope. :P

[Davros El Davros]

Yeah I am running an electronic dizzy, which has kept the tuning fairly even over the last 6 months.

 

After watching my old man mess around with points dizzys on our valiants for the past 20 years, I decided to stick with my electronic dizzy on this engine.

 

 

I was having some issues with pinging because my timing was too advanced, but we worked out the timing and everything has been running sweet for the last 6 months or so,

 

save a few issues with the stock Aisan carby - float level is a bit low which makes the engine stall sometimes when you have to break really hard to stop.

 

 

Ill run the compression test first, then pull off the rocker cover and do the valve stem seals so I can start crossing off things.... :P

[bruce]

I've had a rattle noise in my 5K, it comes on around 3000 rpm, and is more apparent when held at a constant rpm.

Had a few people look at it, and they couldn't figure out what it was. I thought it was noisey hydraulic lifters, so I put some lifter cleaner in, but that didn't work.

 

I've been driving it for a year, and today I went to the mechanic, and the apprentice there thinks it's either piston slap, or wear in a gudgeon pin.

The older mechanic had a listen, and said one of the pistons has had it; cracked.

So time for a rebuild :wink:

 

but yeah, a compression test would give more insight into the problem.

[Davros El Davros]

Hey guys,

 

The rattle in my engine also comes on at about 3000rpm, or when you are coasting down a hill and back off from the accelerator.

 

 

I ran a compression test today and here are the results:

 

Cylinder One:

First registers around 75psi then builds to around 160/165 psi

 

Cylinder Two:

First registers around 75psi then builds to around 175 psi

 

Cylinder Three:

First registers around 75psi then builds to around 170 psi

 

Cylinder Four:

First registers around 75-80psi then builds to around 150/155 psi

 

 

While I was messing around today I also adjusted the timing a little and topped the oil up and cleaned the spark plugs.

 

Jumped in for a test drive and noticed that the problem is still there, but not as pronounced and as often as before....

[coln72]

had something similar with my 5k. Rattled, thought it had a cracked piston on no. 3, so it was stripped for a rebuild. Only nothing wrong with piston no. three :hmm: Had a coulple of engine rebuilders check it out but nothing wrong. Did notice though, that the inlet manifold was cracked on that cylinder. We think that this may have been causing the noise.

[bruce]

I noticed the rattle noise in my 5K is louder when the timing is advanced more.

At 20 degrees its fairly noisey, and setting it to 10 degrees is OK, but the noise is still there.

I drove it daily for 9 months after setting it to 10 degrees, and the noise became progressively quieter, especially when highway driving, but it was because the timing went out to 0-5 degrees.

[greenmac80]

Heeey everyone

 

i'll be watching this closely because you guys are describing the exact noise that

i'm getting in my 4K!

i was thinking valve springs? weak? aka valve bouncing?

[Rollaboy2608]

a cylinder leakdown test will give you a definite indication of where the burning oil is coming from. It may also indicate worn rings, which, while unlikely, could be causing the piston to slap around a bit. That little bit of extra clearance can make a big difference at higher rpm. Otherwise I'd just pull the head off and take a look, doesnt take much to change the head gasket on a K motor

[Davros El Davros]

Yeah pulling the head off is the best way to have a look at what is going on.

 

Just gotta get my hands on a torque wrench and a new head gasket then its happening.

 

Anyone know the proper torque settings for a 5k head?

[camerondownunder88]

Hi,

It is late so can't stay up to explain I get this similar noise in my 3K. Ill post up info I have in the morning.

 

Oh I drive 500km a week in my KE30 with 3K and umm rattle hasnt hurt it yet (touch wood) so mmm just drive it if you can I guess. It is a K motor what can't they do apart from go fast stock..LOL

 

Cameron

[dfunkt]

Davros

 

Click Here for lotsa useful 5k specs :thumbsup:

[Davros El Davros]

Man, wish I knew about this earlier!

 

Have done a few searches but no luck.

 

Thanks!