Loud Tick/Knock after Intake Replacement

[hartdt]

Replaced the plastic intake (was leaking at thermostat housing) with dorman unit on my 99 GT 4.6 litre with 78K. The replacement went well with no issues. Upon start-up the motor is making a loud tick or knock. Removed intake and scoped the intake runners and piston via the sparkplug holes and see no damage (such as if something had fallen in during install). Also compression test on each cylinder showed positive results. (all between 150-160 psi). I am am confident I have the right PI stock replacement intake. The knock gets more prounounced as throttle is increased. Removed the serp belt and the knock is still there when the motor was run momentarily (to see if the water pump or an accessory was the culprit). Other than the knock the motor starts, runs smooth with no hesitation or miss. Can't tell where the noise is coming from (top or bottom, left or right bank, etc).

I have uninstalled and reinstalled the replacement intake twice with the same result of the knock...have not tried to put on the old unit to see if the noise is replicated yet.

Any ideas on what direction to go in now? Thanks in advance for your help...

David

 

[Jason5.0]

could you be hearing an exhaust leak from your egr tube? exhaust leaks can sound like a loud tick sometimes. run your hand beside the tube and see if you feel a breeze, and start it in the cold and look for steam. just a thought...

 

[hartdt]

May put it back together in the morning with the original intake. Will look for the egr leak then. It seems to be more serious though. Thanks.

 

[hartdt]

Bumpkus

 

[fast97gt]

My 00gt did after my brother replaced the plastic intake, we never did figure it out because it went away after a few minutes. It came back less the 50miles of driving, went away. Then pop went the weasel, dropped a valve due the chain guides be wore slap the hell out, it was catistrofic failure. The whole engine had to be replaced but that's the thing I could think of was ptv issue, maybe the guide tensior leaked down? But nope it has a fali safe lock so that can't happen. Then it all pointed to the chain guide being badly worn on the passenger side. In the 2yrs since I've seen more then a dozen windsor(99/00) motors that have done this. IDK I really would like to know why and what myself.

 

[hartdt]

Thanks for the reply. I have a couple of others suggest this as well. They have told me to listen for the noise on the front passenger side of the motor. They had seen 6 other motors with same issue. Had one guy today suggest it was a lifter on passenger side bank. Hopefully we can pinpoint it soon.

 

[hartdt]

Bump. Any other ideas? The tick did seem to get quieter today after driving. Did add about 1/3 bottle of seafoam to the oil the day prior. Former ford/toyota mechanic is pretty confident the noise is caused by a worn timing chain guide causing the chain to hit a bolt head or something. Thinking of taking the car to ford to get a second opinion. Any thoughts?

 

[nyuk98gt]

hartdt:

You can use a piece of Tygon tubing to pinpoint the noise. Just put a piece of tubing up to your ear and move the other end around until you zero in on the noise. Watch your fingers around the belt and pulleys!

Chris

 

[hartdt]

Local mechanic initially thought the noise was associated with the timing chain but after further review he now believes the noise is the piston wrist pin on the #4 cylinder. He is working on m repair options. The compression is good on all cylinders. I am hoping that if the oil is drained and thefilter is cut open and no metal shavings are found or significant sludge is found int the motor that I could get away with just replacing the rod and piston. The car has 78k miles and I am not interested in building it up. Just want it to run well. The mechanic indicated you have to pull the motor to change out the rod and the piston. I have read that you can support the motor and remove the k member and perform the job with the engine in the car. Any thoughts here? Am I wasting time and money trying to fix only the wrist pin issue versus a full rebuild? What about having to pull the engine for this job? Should I really be thinking about just replacing the motor? To think the car ran great before I replaced the intake. Could I have caused this?

 

[trombonedemon]

Is there a possibility that something small and metallic could have fallen into the car's engine, if so, time for an engine overhaul.

 

[BurningRubber]

Wristpin is pretty damn serious to jump to as a conclusion. There's no reason that an intake swap would cause the wristpin to go bad. That'd be extreme coincidence that it failed upon re-starting after the intake swap. Also, at 78k, unless it's been abused or neglected, you shouldn't be seeing any type of timing equipment or wrist-pin failure.

Now, if you sucked something in the engine (washer, bolt, nut, etc.), then that of course could have done catastrophic damage.

How well do you know this mechanic? Been to him before? It's not hard to him to tell you it's a wrist-pin, when in reality it's something minor, and to take you for a $ ride.

As far as the engine, removing the engine is safer than lifting the car up and supporting the engine via engine hoist or brace. It's also kinda hard to see what you're doing looking up into the engine from underneath and trying to replace all of that. The rod/piston could be dropped out with the engine in the car to my knowledge, but it's not the desire-able method.

 

[trinity_gt]

http://www.stangnet.com/mustang-forums/830097-does-my-96gt-have-blown-headgasket-what.html

An extreme example of detritus getting into an intake port and ruining an engine. 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.

 

[hartdt]

I scoped the spark plug holes and did not see any nicks or scrapes or metal shavings etc. The sparkplugs look normal. I put paper towels in intake runners then vaccumed them out prior to reinstall of the intake I have accounted for all parts and bolts. Guess I somehow have made a major mistake here. Should I be starting to look damage somewhere else prior to the wrist pin then?

 

[BurningRubber]

Ring-land wouldn't be hard to break if debris got in there that didn't get burned up (such as a small piece of paper towel).

Are we sure it's not an issue with the timing equipment?

 

[ItsStock02]

My buddy and I replaced the IM gaskets on his 99 I would say 1.5 years ago. Everything was fine before, after the swap his engine made a horrible ticking noise and runs really rough. We thought something might have got in an intake port. I dont see how a timing chain guide could go bad in that short time.

Anyways we never did figure it out and the car has been sitting ever since.

 

[BurningRubber]

I vacuumed out my intake ports probably 3-4 times, I was flipping out that something could have dropped in there.

 

[bhuff30]

Wrist pin failures are extremely rare in modern engines. I think it is very unlikely a wrist pin just happen to go bad when you restarted your engine after an intake swap. There just isn't a correlation and it makes no sense.

What is the frequency of the knock? Once every revolution or once every 2 revolutions? That will tell you if it is valve train related or not because the valve train turns half the speed of the crank.

Have you inspected the areas around the accessory belt? If you remove the belt, does it still knock?

You checked the spark plugs to ensure they are seated well?

 

[hartdt]

The tap/knock sounds to me as if it is with every evolution...I have had multiple mechanics now listen to the car (including a 26 years fomoco mechanic and another long time toyota/ford mechanic) and their last general consensus was that it was a timing chain sound...as of now a friend (ford/toyota mechanic - laid off) is pulling the motor apart to further diagnose the issue...after pulling the passenger valve cover, he says he sees on one side of the time chain (as it rolls over the cam gear? I suppose as the front timing cover was not removed yet) appears to be rubbed clean of oil vs the other side is has oil on it as if the chain is rubbing against something...he will be removing the timing cover today...it just seem so odd that the timing chain would suddenly become an issue after I replaced the intake...seems much more likely that that some trash or paper towel would have been sucked in via the intake runners and damaged a valve or spring or lash adjuster etc...I guess I have only guarded optimism it is a timing chain or tensioner issue because the noise sounds much more serious than this...one other original diagnosis was a wrist pin on the #4 cylinder...seems amazing to me that the sound these guys are hearing is so distinct from the #4 cylinder all the way up to the timing chain area in front of the passenger side cylinder bank...we did remove the serp belt early on in the diagnosis and the knock/tap was still there...any other thoughts would be appreciated...

David

 

[hartdt]

The sparkplugs were seated well and were clean with no damage. Forgot mention this on the earlier post.

 

[hartdt]

Ring-land wouldn't be hard to break if debris got in there that didn't get burned up (such as a small piece of paper towel).

Are we sure it's not an issue with the timing equipment?

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