Slight Ticking Sound and Misfire on Cyl 6 Error Code

[mbs xk8]

Hi All... Quick question about my '99 RR with 175,000 miles. I have a service engine soon light for P1316 and P0306. The engine doesn't idle very well.... well it idles better now that I've changed the oil, spark plugs, wires, and the MAF sensor. But there's a slight tick sound from the valve cover area near cylinder 6. The tick increases with speed.

Is there a lifter that's sticking? I don't think it's serious enough (or loud enough) to be a bent or broken rod. The SUV doesn't seem to have a lot of get up and go. I just purchased her and knew there would be issues, but I really love the view and the ride from the driver's seat.

I have an old '75 MG Midget that I've adjusted the valves on. Do the valves on a RR need to be adjusted too?

Any idea what the ticking could be?

I really appreciate any help you can provide!

Thanks...

[Jos Geuze]

Hi

The valve lifters have hydraulic tappets and are filled up by the lub oil pressure continuously which fills them with oil and takes out all the clearance between the cam and the rockerarm. When the valve is being operated by the cam non return valve in the tappet prevents oil from flowing back and the tappet in extended form is becoming part of the linkage to open the valve.

You can remove the valve covers and run the engine at tick over and you will see it when i the tappet is not extended.

An other possible cause of ticking is a loose liner. The liners are steel bushes in the aluminum block in which the pistons move up and down. If the engine has been overheated it is possible that the steel liner has come loose and is moving up and down together with the piston. This will also cause coolant to leak into the combustion chamber and combustion gasses into the coolingwater circuit. The signs of this fault is rock hard rubber hoses when the engine is running and loss of coolant without having a leak. The combustion chamber and spark plug of the cylinder with the slipped liner are steam cleaned. If glycol antifreeze is used in the cooling system the engine can also start burning the glycol and the self combustion of the glycol makes the engine sound like a diesel.

Regards

Jos

[leftlanetruckin]

Open the hood in the dark and see if there is any arcing going on with the plug leads. That makes a ticking noise when the spark is grounding out from the boot etc.
I would be looking at a lifter more than a slipped liner myself, assuming there are no more symptoms?
If the lifter are the OEM ones, they have served you well IMHO.
Give it an oil change to some 10w40 and see if that cures it. Any worse on initial startup than when its warm?

Martin

[mbs xk8]

I changed the oil to 10W40 when I purchased it. Still makes the exact same sound. When you say run the engine at "tick" what do you mean?

Should I remove the valve cover and start the engine to let it idle?

Also, there's no spark. I looked in the engine bay tonight and couldn't see anything. I've put in new sparkplugs and wires.

Thanks!

[Jos Geuze]

Hi

With run the engine at tick over means let it idle and run at the least possible revolutions which is around 700 rpm on the range rover 4.6 and 4.0.

Regards

Jos

[WayneB]

A coil pack that is arcing out can also produce a ticking noise and rough running.

[mbs xk8]

Update: I've checked and I'm getting a spark at all plugs (2,4,6 and . But the spark at cylinder 2 will leap out of the boot at about an inche from metal. The boot has to be very very close to metal at cylinders 6 and 8.

Also, when I clear the codes with my code reader, I can drive for 15-20 miles before the service engine soon light appear and I get the P0306 and p0300 codes again

Any ideas?

Thanks

[triplb25]

What plug wires do you have?

[mbs xk8]

The ticking was evident on the wires that were on the RR when I bought it 3 weeks ago. It continues with the new wires I purchased at NAPA. They were the beat quality NAPA offered and have a lifetime warrantee. They are 7mm I believe.

[wreckrunner]

P0306 is misfire at cylinder #6 detected, very specific, however, P0300 is random multiple misfire detected. If you are certain the wires are good, I have had quite a few new aftermarket parts that were bad, again, if the wires are good I would look at the wiring connections at the coils and if they proved sound maybe think about changing the coils.

[triplb25]

P0306 is misfire at cylinder #6 detected, very specific, however, P0300 is random multiple misfire detected. If you are certain the wires are good, I have had quite a few new aftermarket parts that were bad, again, if the wires are good I would look at the wiring connections at the coils and if they proved sound maybe think about changing the coils.

See my post "ses codes"

[carcharodon]

Your lacking some info.. how many miles on the truck? Does the tick happen right away when started or only when you get up to operating temp? Is it light and metallic like a valve clearance issues or deeper like a knock, is it only at idle? All revs? when you goose it say up to 3500 and let the idle fall does the noise subside then return when it idles?

Tick at cold startup, goes away when warm= collapsed lifter

No tick at startup, ticks at temp, goes away sometimes when revs then idles down=slipped liner

Tick all the time=slipped liner, worn camshaft/lifters,or failed rocker

Deep tone= sounds like a deisel only less big end con rod

Tapping after you've spent countless hours and funds chasing a "failed lifter, camshaft, oil pump" = wrist pin, slipped liner, collapsed piston skirt.

Tick after you've replaced/rebuilt motor=broken catalytic converter.

If you can't diag and repair on your own there is no cheap way out of this. Pull the intake and valve covers,remove rockers inspect for loose cups, pull lifters(remember where they went, please) inspect lifters for cupping, check camshaft lobes, pull oil pan clean the sludge (there will be sludge) check oil pickup tube for debris, remove oil pump, fix it. Put it all back together, pray. If that doesn't work, replace motor or part out P38.

In the end the cheapest way is will be, buy a reman'd engine, buy a case of beer for you buddy the mechanic and spent the weekend replacing the motor. Still cheaper than a used P38 or chasing your tail.

Ask me how I know all this.

PM me I need some interior bits..

[mbs xk8]

Wow, that's depressing! It's a 99 RR 4.0 with 176,000 miles.

Today, I switched the ignition coils to see if the misfire would transfer. I cleared the codes and drove for 40 miles (city) before the SES light came on. Checked the codes and still have 0306 and 1316.

The ticking isn't present when the engine is cold. It get louder as you accelerate. It is a light tick-tick-tick that sounds like my wife's volco xc90 engine a little. I can hear several light ticks from the left valve cover and just the one tick from the right side.

Might the error codes be unrelated to the ticking? Perhaps I have a bad injector at cylinder 6 and a bad valve at one of the cylinders on the right side of the engine?


Maybe I should try and record it and post the video.

[leftlanetruckin]

Dont get too depressed just yet, there is a lot of useless and incorrect information in Debbie Downer's post.
Miles are irrelevant in my EXPERIENCE, so dont get hung up on that neither mate. Maybe he had a slipped liner etc, but the vast majority are not a liner or HG issue. And to be honest, I get kind of sick hearing the " head gasket failed" messages every week. I have personally lost 2 rebuilds due to the owners automatically thinking that the HG had failed, when it had not. They jsut read the BS on forums and thought they failed on a weekly basis.
Unless the motor has been cooked and run out of coolant, keep investigating.

Martin

[carcharodon]

Dont get too depressed just yet, there is a lot of useless and incorrect information in Debbie Downer's post.
Miles are irrelevant in my EXPERIENCE, so dont get hung up on that neither mate. Maybe he had a slipped liner etc, but the vast majority are not a liner or HG issue. And to be honest, I get kind of sick hearing the " head gasket failed" messages every week. I have personally lost 2 rebuilds due to the owners automatically thinking that the HG had failed, when it had not. They jsut read the BS on forums and thought they failed on a weekly basis.
Unless the motor has been cooked and run out of coolant, keep investigating.

Martin

Debbie Downer never said anything about head gaskets.. mine at 209,000 had nothing wrong with it EVER, head gaskets were fine, aside from coil spring conversion all it ever got was regular maintenance.

Debbie was merely giving likely scenarios not absolute fact, of course he might get away clean with it just being an injector, maybe a stuck lifter, worn cam lobe.... easy fixes... maybe. Debbie is simply of the opinion that one must have a clear understanding that if these motors are not maintained regularly they are headed for certain death. Typically at great expense prior to, you know that. There aren't inherent faults poorly engineered into these trucks how can that be? How many countless LR v8's have been produced and are still operating just fine today? possibly most myths are propagated through the forums by uneducated members, bad experiences, dealer techs and service managers quick to misdiagnose an issue and simply replace.

Debbie also never diagnosed his problem, and she certainly doesn't take what ANYBODY says on these forums as gospel.

How are miles irrelevant? Your saying that lifter/cam wear, timing chain stretch aren't an issue with higher mileage motors? That poor maintenance practice over a long service life won't take its toll on an engines performance. Sure mileage might not matter. Take mine for example, still ran like a champ, averaged 18.5 highway 12-13 city at 209k, but ticked like a *******. Those 2 lost rebuilds what was it in the end? We know nothing about this guys motor, what condition its in, what the service history is. Debbie laid out real world scenarios and she certainly isn't going to coddle anyone, nor make excuses. Hopefully for his sake she is wrong, I hate to see another one go to the junkyard. Maybe we can at least agree on that?