2001 SVT Cobra making weird slap noise after Forged+Cam rebuild.

This is my 2001 SVT Cobra I have been working on for about 7 months. Engine about 0.030 Bored over, Crankshaft shaved .030/.030 K1. Technologies H-Beam Rods,,Kings XP Bearings, Ford Racing Timing Kit(A few timing components were upgraded from stock to Billet.) D.S.S Racing Pistons, Heads were redone and have Howard Cams+Springs/Retainers upgrade, 255 LPH Fuel Pump, Ford Racing 47# EV14 injectors*They are compatible plug and play with ev6*, SCTX4 Hand Tuner, Dan at ProDyno got me a first start tune for all my mods. Exhaust is BBK Long Tube Headers+BBK O/R H-Pipe + Stock Catback/Muffler. CAI Intake into the fender. BBK Twin 62mm Throttle Body, 1 Inch Intake Spacer, Exedy Mach 350 Stage 1 Clutch, BBK Adjustable Clutch Cable, Quadrant & Firewall Adjuster, Exedy Lightweight Racing Flywheel, MMR Ford Billet Rear Main Seal Housing cover, ON3P Coolant Cross Over Delete, MMR Light Weight Power Steering Pulley, MMR Head Cooling Mod, SR Lokar Flexible Dipstick---*If You Have Long Tubes, You Will Love This*, Ford OEM Coil Packs*I Heard OEM coil parks were reliable*,NGK Iridium IX Spark Plugs* Thinking about going to Copper Plugs and changing them more often*.


Just Watch this Video(This video shows the Driver side, Which Was at first making the noise, but has now gone quiet and the noise transitioned to the passenger side very front of the valve cover) .. The tune is probably not too good it was just put together and I uploaded it with my SCT x4. But he told me to bring it back to him as soon as I can and he can get a good tune with it on the dyno(under 4000 rpm). Maybe this is PTV issues(Time to pull all plugs and check for Visible dents from valves???). Maybe this is a stuck lifter, collapsed lifter or the lash adjuster isn't getting the oil it needs? Maybe its my Oil? Royal Purple break In convention oil 10w-30. Maybe the timing is off by a tooth? Or. Maybe the timing isn't degreed properly with the cams?. Or this sound is normal with what was done to my engine? When I drive it, it quiets down slightly and just blends in with the other noises. Every Pulley except A/C is new.

Good job telling us all youve done to the motor, very impressive. But very hard to tell by listening to the recording. Need better description of what kind of a noise it is---did it sound that way from the beginning, what is the oil pressure, what rpm does it make the noise--like only idle or all the time, have you checked for exhaust leaks, is the engine missing, does it accelerate smoothly, have you done a compression check, did it transfer from one side to another or is it now on both sides?

It could be a number of things from a bent valve hitting the piston to a flattened cam lob, a spun rod bearing or a broken piston ring which could have been caused by a bad installation or tolerances/piston clearances too tight. If I was to go by just the sound I hear in the video I would say oil starvation to the top or bottom end which may not be connected to oil pressure but a clogged or blocked oil passage. You better not drive it and have a professional diagnose the problem because anyone here can only guess.

do the heads have original lash adjusters? sounds just like my car.

Sent from my SM-G930V using Tapatalk

FIREBALL said:

Good job telling us all youve done to the motor, very impressive. But very hard to tell by listening to the recording. Need better description of what kind of a noise it is---did it sound that way from the beginning, what is the oil pressure, what rpm does it make the noise--like only idle or all the time, have you checked for exhaust leaks, is the engine missing, does it accelerate smoothly, have you done a compression check, did it transfer from one side to another or is it now on both sides?

It could be a number of things from a bent valve hitting the piston to a flattened cam lob, a spun rod bearing or a broken piston ring which could have been caused by a bad installation or tolerances/piston clearances too tight. If I was to go by just the sound I hear in the video I would say oil starvation to the top or bottom end which may not be connected to oil pressure but a clogged or blocked oil passage. You better not drive it and have a professional diagnose the problem because anyone here can only guess.

Click to expand...

Hey mate I appriciate the detailed response, I’ve actually already driven it atleast 25 maybe 30 miles, when I got back from a nice nights drive ( her first drive) she sounded normal, and the slapping noise went away to almost nothing( but comes back when you leave the car off for a while). Also this morning I have a no Start condition if you wanna take a look at my latest video on my YouTube channel( it’s only 8 seconds) but a Crank but no astray.

FIREBALL said:

Good job telling us all youve done to the motor, very impressive. But very hard to tell by listening to the recording. Need better description of what kind of a noise it is---did it sound that way from the beginning, what is the oil pressure, what rpm does it make the noise--like only idle or all the time, have you checked for exhaust leaks, is the engine missing, does it accelerate smoothly, have you done a compression check, did it transfer from one side to another or is it now on both sides?

It could be a number of things from a bent valve hitting the piston to a flattened cam lob, a spun rod bearing or a broken piston ring which could have been caused by a bad installation or tolerances/piston clearances too tight. If I was to go by just the sound I hear in the video I would say oil starvation to the top or bottom end which may not be connected to oil pressure but a clogged or blocked oil passage. You better not drive it and have a professional diagnose the problem because anyone here can only guess.

Click to expand...

If you can/want, check my YouTube for my first start videos, and my other videos to hear the sound, you could hear it on the very first start up. It makes sound a few seconds AFTER I start it up, NOT IMMIDENTLY, a solid 3-5 seconds then it starts that sound. NOTE*THE SOUND HAS SWITCHED POSITIONS LIKE I STATED, went from Driver side valve cover to mow the passenger side Valve cover* it only makes it at idle, when revved above like 1500 it goes away. It also goes away after you drive it I have noticed, The engine also shakes a bit, you might notice it from the video, what the hell makes the engine shake that bad?? No vibrations felt through the steering wheel, BUT some are felt through the shifter. I doubt it is an exhaust leak., and yes it accelerates REALLY smooth to my surprise, ive only taken it to 4000rpm, but man it’s hard to stay under 4000rpm she eats the Rpms like it’s nothing, def has the power I expected (I’ve only been to half throttle pull from 1k to 4k). No compression check has been done. TOMORROW I do plan on getting new spark plugs and checking to see how those are doing( I checked 1 and it looked like it was running rich, but looked great).

EDIT- also I watched the guy build the engine, I don’t think he degrees the cams, if I’m correct he just lined the dots up on the cams and put the timing chain on, but I don’t know if that could cause PTV, also I don’t even know if that is PTV because it goes away past 1500RPM. One thing I can say is she sounds like a Sexy Cummings, purring when she is warmed up. ALSO, it’s a top end only sound, you really can’t hear it if you stick your head under the car. ALSO IT DOES NOT MAKE ANY SOUNDS WHEN JUST CRANKING. Cranking may not spin the motor fast enough to hear the noise, but there’s no noises when just turning the engine.

wkornf said:

do the heads have original lash adjusters? sounds just like my car.

Sent from my SM-G930V using Tapatalk

Click to expand...

To be honest I hope they aren’t used, but the guy just “rebuild” my heads, New valves, rocker arms, springs, retainers. I hope he didn’t reuse old shit. I got to see him build the engine and everhing in the head looked spotless and shiny

New lash adjusters are very expensive. I doubt they replaced them. they are what keep your followers from clacking around.

Sent from my SM-G930V using Tapatalk

wkornf said:

New lash adjusters are very expensive. I doubt they replaced them. they are what keep your followers from clacking around.

Sent from my SM-G930V using Tapatalk

Click to expand...

You might honestly be correct, I know Howard Cams double valve springs, steel retainers, rocker arms were installed, but I gusss they could of kept some stuff original. Car only had 40k Miles when it blew.

wkornf said:

New lash adjusters are very expensive. I doubt they replaced them. they are what keep your followers from clacking around.

Sent from my SM-G930V using Tapatalk

Click to expand...

Do you think I’d be ok putting some more miles on the car? Or should I just tear it down again and replace the Lash Adjusters, they don’t seem hard to replace, just a good full solid days worth of work

Was a new oil pump installed---what brand? It would be a good idea to check oil pressure with a mechanical gauge at start up, after warm up and idle when hot.

FIREBALL said:

Was a new oil pump installed---what brand? It would be a good idea to check oil pressure with a mechanical gauge at start up, after warm up and idle when hot.

Click to expand...

honestly if you have a fresh built motor and don't have a oil pressure gauge on it there could be Major issues. this right here is step 1. the dummy light in dash is worthless. b

Sent from my SM-G930V using Tapatalk

The factory gauge is pretty much worthless also, it only tells you there is some oil pressure not how much. It really was surprising that an SVT Cobra didnt come with a real pressure guage.-----So what is your oil pressure when cold and hot.

FIREBALL said:

Was a new oil pump installed---what brand? It would be a good idea to check oil pressure with a mechanical gauge at start up, after warm up and idle when hot.

Click to expand...

Yes sir, we T'd off the oil pressure sensor and installed a cheap mechanical oil pressure guage and it read 80psi on start up, dropped to about 65ish after it idles for a little bit, then dropped to 40psi, then dropped to 20psi.
Ford Performance High Volume Oil Pump from BBK WITH TSS Racing oil pump gears.
I encourage you all to look at my First start Idle Video and the noise isn't that bad.(In this video my Throttle body kept getting stuck)

FIREBALL said:

The factory gauge is pretty much worthless also, it only tells you there is some oil pressure not how much. It really was surprising that an SVT Cobra didnt come with a real pressure guage.-----So what is your oil pressure when cold and hot.

Click to expand...

80psi First start of the morning, itll drop to 65ish pretty quick, then slowly drop down to 40 when it's warming up, then drops down to about 15-20ish when it's warm, any amount of throttle and the gauge spiked to at least 50psi immediately, accelerating to about 3900, the oil pressure would climb to bout 50-60ish. After that we took the oil pressure gauge out and put it back to normal. I want a digital electric gauge but can't afford it after spending all my money on this car, but I guess I'll go run it back through the cabin just to be sure I can monitor my oil pressure to the best accuracy

If anyone is wondering how it is doing, I couldn't get it to start, pulled all plugs out, EVERY cylinder was dirty as hell and has very small chunks of dirt on top of the pistons, and about 3-5 of them had fluid in them. The plugs were just wet but looked good( i only have like 35 miles on the car so far) So changed plugs to Copper Plugs(Gaped from .55, what I first had, to .46 roughly). She fired right up on the first crank and that noise went completely away and she was quiet as can be, BUT she also wasn't loping with the cam and had a high idle, As I mentioned in earlier posts the noise only comes from when it's idling around 1000rpm or lower. But unfortunately the car does this odd thing sometimes, it will idle for 30 seconds around 1300-1500, then it will slowly surge up to 2000 for a second, then drop back down to 1000, and then begin to bog down and die. When it does that, you are able to keep the car running with the throttle cable pedal, but when you let off the pedal the car won't hold an idle on its own, it just starts to lope with the cam for a second then bog down and die within a few seconds, (New IAC, new TBPS, Cleaned Throttle body(I won't deny this throttle body blade is corroded slightly around the edge, I will provide pictures if anyone is curious to see how it looks, BUT I think it will do for now)( ALSO there is a little stud on the throttle body that controls where the blades sit at idle, I had a sticky throttle cable, so I adjusted the stud a little to have the blade sit open a tiny tiny bit more than stock. (About a 5 or so turns on the stud) so the throttle cable wouldn't get stuck, But please take this into consideration(I had the car running pretty decent last week, she would idle and drive no problems, hence why I have put only about 35 miles on it, breaking it in easy, but the alternator went bad, car kept losing power when driving(voltmeter in dash kept going down to L then car would die and steering wheel would lock up) and she died a lot, so she sat for a few days, my buddy said I didn't plug in some sensor, sad it took him a bit of looking to find it, no idea what that sensor was tho, it fired right up and I drove it home, stopping by AutoZone, she only died on me twice, but I also had my foot on the clutch for 1 of the time so it might have been my fault. After that, I drove her home and when I pulled in to the driveway It shut it off, so I cruise into my parking spot, let the car sit for about 10 minutes, ( The video below is what happens next). ( ALSO LET ME MENTIONS SOMETHING I FIND INTERESTING, she was doing this 100% extract same things before the alternator went bad, idle fine for 30 seconds, idle surge for a second, then RPMs drop and the car dies, the way I fixed it was with a new battery, I think, Because the Alternator and Battery are both New. ANY HELP OR ANY COMMENTS are appreciated, I think anyone who is reading and responding to my posts, PLEase, watch this video This video was shot around 10am yesterday morning.

Hello, If anyone wants an update. New plugs. The noise has oddly gone away, she won't idle now. She just bogs and can't hold it. I can only blame the tune? I have no idea honestly. OH ALSO, did some driving about 30 minutes, data logged. 216F was max temp reached during that 30 min drive, without a hood in about 73 degrees and without being able to idle. We had to rev the rpms at stop lights so, revving for 2 minutes waiting at a damn stoplight isn't gonna help the temp. Duty cycle stayed right at .15-.23 with maybe quarter throttle to a little under half throttle in all gears up to about 3000-3500 rpm. Still gonna baby it until a couple of thousand miles. Voltage was good the entire time, and also the Idle rpm was at 800-1200. I was data logging all this using the SCT X4.

when my SCT shows Temp above 210 I start to get worried. before I upgraded my radiator it got to 220 or so and my timing got locked out. i guess it was some sort of limp mode to lower temps. For what it's worth I Cruise at around 190F lately


Sent from my SM-G930V using Tapatalk

Get your tune figured out before it causes any further problems/damage.

2DXTRM said:

Get your tune figured out before it causes any further problems/damage.

Click to expand...

I agree I don't wanna drive it anymore without the tune. Well, I called Pro Dyno and may the 9th is when I will bring it to them for a good driveable tune for under 4000rpm. The only thing that sucks, Is it is about 10-15 minutes on the highway and 8 mins in stop and go traffic to ProDyno. But I assume ill be fine babying it up there.