Loud Tick/Knock after Intake Replacement

[trinity_gt]

Could you clarify what Ring-land means? Thanks...

The ring-land is the area of the piston between the circumferential grooves where the piston rings sit. The top ring land incorporates the area above the top ring and is thus exposed to combustion pressures (including detonation) as well as any debris that enters the combustion chamber.

A top ring land can break, such as on this Brand X LS motor:

On 2V mod motors, the piston is cast from very brittle material (aka "hypereutectic") and the top ring land is very thin (so Ford could get the emissions down by reducing crevices in which unburnt HCs can hide...):

The thin and brittle material means its not hard to snap the top ring land due to detonation (e.g. too much boost, not enough octane, too much timing, not enough fuel etc etc) or if something solid got into the chamber.

 

[fast97gt]

its not the tensioner itself, its due to the tensioner being worn so much the engine is out of time. thus causing the ptv issue and reason your hearing the noise in #4 cylender location is because thats the piston thats slapping a valve

 

[hartdt]

Well my mechanic called today and said that one of the timing tensioners has failed. He said there was 1.5 inches of slack in the chain and it was slapping the cover or the guides and this was also causing the tap/knock noise. Is it possible then that we should also pull the head and check the condition of the #4 valves and piston? Or once the timing system is repaired and the timing is back to spec will it be ok? The car ran good prior and has good compression. My mechanic also recommended we replace both tensioners all guides and the chain itself. He felt if one tensioner failed the other may fail again soon and I would have to tear the engine down again to repair. This seems to make sense but wanted to see if you guys would replace only the one failed tensioner and maybe a worn guide vs replacing everything. He using only new ford parts and motorcraft filters and fluids on the repair (this also includes a tranny drain filter and replacement of a leaky tran pan gasket). Total charge for whole is $1100. Does this seem reasonable or am I getting taken? I hope this repairs the car. He is 99.9 percent sure this is the issue. Any thoughts? Thanks to all for your help and guidance up to now.

 

[bhuff30]

The chain can definately make a loud knock type noise when loose. I had some slightly worn chain guides and it clearly knocked on cold mornings until the engine was a bit warmer. In your case, where the tensioner completely failed, the chain will make a loud racket. Just be happy the problem was diagnosed and solved before causing serious damage. I'm sure he will carefully inspect and replace the guides too. Since it is open, just replace them.

I would think your #4 valve will be fine. After everything is put back together, you can run a compression check to be certain. If the compression is fine, then the valve isn't bent and still seals correctly. Also, a single valve is unlikely to be damaged... it would be all of one type on that side of the engine since the timing for each valve is suppose to be the same.

The price seems reasonable to me. I spent about 16-20 hrs replacing my cams and chain guides. It is a rough job. Of course, it was my first time replacing these parts and I was being very careful because it is my daily driver, but it is NOT an easy job.

 

[fast97gt]

1.5in of slack im willing to bet theres damage, if not now maybe prolonge damage.

 

[hartdt]

Is it possible for their to be valve damage even though the compression was tested good on all cylinders? Just don't want to get my hopes up that the timing chain replacement will solve my problems if this is not feasible. My mechanic is also doing an engine flush to remove excessive sludge he sees. Is this a good idea?

 

[fast97gt]

compression tests can mislead, the real way to find ptv damage is vacuum leak down. i find it hard to see the tensioner failing, there is a fail safe mechanism made on them so they dont leak donw. im doubting the skills of your mech, but i would replace chains, guides, tensioners, and gears. the tensioners work off the oil pressure from the engine oiling system. might be wise to drop the oil pan and check the pick-up screen for the oil pump for clogage.

 

[hartdt]

Well as some of you thought and I feared replacing the timing chain system did not eliminate the knock. The mechanic still is confident that the noise is not coming from the bottom end. He is now going to pull the valve covers and begin to investigate the rockers and then move down to the valves etc. What a disappointment. No metal in the oil. Still the same knock. Am I wasting money and time on this effort? Could it be a costly wild goose chase? I will suggest the cylinder leak down test as well. What should he be looking for going forward?

 

[fast97gt]

ok ok ill say it a different way, when your chain had slack in it, you had ptv issues. thats what caused the engine to start the noise. now youve fixed the timing chain isuue you have other issues. ie bent valve, cracked piston, etc.

 

[midnightdriver]

Well as some of you thought and I feared replacing the timing chain system did not eliminate the knock. The mechanic still is confident that the noise is not coming from the bottom end. He is now going to pull the valve covers and begin to investigate the rockers and then move down to the valves etc. What a disappointment. No metal in the oil. Still the same knock. Am I wasting money and time on this effort? Could it be a costly wild goose chase? I will suggest the cylinder leak down test as well. What should he be looking for going forward?

First question is why didn't your "mechanic" pull the valve covers off when he replaced the timing chain system? I am pretty sure that is a required step. The timing on these cars are very sensitive. Are your sure it the same knock? Because early you said it was a tick not a knock. A knock sound is way different then a tick. I have personally heard rod knock, piston slap valve tick, timing chain slap and PTV impact and they all sound very different. Although I could not ID them on sound alone, not that good of a mechanic, I did notice a change between them.

My take on this situation is when you originally took on the intake swap some coolant got into your cylinder and you compressed water ( which can't be done) and you messed up your valve or piston. Because if you just swapped intakes, there should never be a change instantly. Instant change means something went wrong in the install process, timing chain failure is usually not one of them. Intake swaps on these cars a fairly common for your type of leak and its a fairly painless procedure.

My suggestion, take a video to document the sound and post it here so that more insight can be offered because we can't "hear" what you are hearing.

 

[hartdt]

First question is why didn't your "mechanic" pull the valve covers off when he replaced the timing chain system? I am pretty sure that is a required step. The timing on these cars are very sensitive. Are your sure it the same knock? Because early you said it was a tick not a knock. A knock sound is way different then a tick. I have personally heard rod knock, piston slap valve tick, timing chain slap and PTV impact and they all sound very different. Although I could not ID them on sound alone, not that good of a mechanic, I did notice a change between them.

My take on this situation is when you originally took on the intake swap some coolant got into your cylinder and you compressed water ( which can't be done) and you messed up your valve or piston. Because if you just swapped intakes, there should never be a change instantly. Instant change means something went wrong in the install process, timing chain failure is usually not one of them. Intake swaps on these cars a fairly common for your type of leak and its a fairly painless procedure.

My suggestion, take a video to document the sound and post it here so that more insight can be offered because we can't "hear" what you are hearing.

I would expect your take to be as reasonable and likely as any other I have heard...the car is still at the mechanic being torn down at this point...the mechanic did have to pull the valve covers in order to replace the timing chain system but when I inquired regarding as to if he looked in detail at that area, he said he did not after seeing/feeling slack in the chain and determining that was the issue...I suppose hopefully he can find an issue within the next steps of removing the heads...he was thinking a broken valve spring, worst case a broken valve or piston?

 

[hartdt]

Well, the short story here is we found a piece of metal embedded in the head from the #1 piston...not clear where it came from...ended up replacing the #1 piston and regrinding the crank, replaced all crank bearings, chem cleaned the block and heads, installed a new set of rings, replaced all of the lash adjusters, and a complete new timing chain assembly. Car runs and sounds strong as it should for a fresh rebuild. Wanted to retain the original engine as the car is a 1999 35th anniversary limited edition...I understand I might have been able to replace the motor for less money with a salvage or even in some cases with a new motor....total cost for parts, labor for the rebuild (including tranny flush/filter change) set me back $2500. Got a 6 month/10K warranty on parts/labor...did I do OK or get taken? Very happy with the car now...

 

[trinity_gt]

I doubt yours is a wrist pin. My bet is something dropped unknown into a port and is now lodged in the piston crown, kissing the top of the chamber every time the piston comes to TDC.

 

[BurningRubber]

Glad it got fixed, but if the engine was already apart, I'd have at least replaced all of the pistons and probably gone a .020 overbore to ensure the cylinders were completely fresh.

I'm guessing most of the expense was labor, so in reality, you probably didn't get hosed but I personally would have gone through the whole engine.

Important thing now is to drive it and enjoy it.

 

[trombonedemon]

When your right, your right. That was one my guesses too, that something was dropped into the intake, whatever.

O.p. Your price seems average for a complete car engine rebuild; new bearings, pistons, engine boring, oil pump, gaskets and seals, rings, cylinder sleave and engine machining. The cost of engine removing and puting it back, towing, refurbished heads.
Lets see, carry the one, devide by 3, counting four fingers and a thumb. The total for me was 3500 bucks.
Cars can cause very stressful times.

 

[fast97gt]

being able to retain the origianol engine on an anniversary car is gonna be the smartest thing you can do, unfortunetly on mine it wasnt an option unless i had the block sleeved. 2500 is a great price around here, especially aroun here and with a warranty...wow

 

[DoctorDyna]

I registered just so that I could share that I've just experienced the exact same issue. I've got a 97 crown vic. Started off what should have been a simple coolant hose replacement because they have that goofy coolant line that goes from the back of the water pump, underneath the upper (plastic) intake and out the rear of the engine. After replacing this coolant line and reinstalling all the parts, I now too have this extremely loud TAKA TAKA TAKA TAKA that sounds as if it's twice per piston stroke.

I think we may have accidentally gotten coolant down into a cylinder and it's bent or broken a wrist pin.

Here's a video, if anyone can confirm my suspicion, or has another idea, please let me know. Should I start looking for a place to rent a cherry picker?

YouTube - Ford

You'll have to excuse my buddy's anti-fordism, he's not a fan