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Discussion Starter #1
At 2200 rpm i get a knock out of the driver side head and it stops at 3500 give or take a little. Also when i put my foot in it it stops no matter what rpm im at. I have never been inside of a mod motor and it sounds like i have a bad lifter but im not really sure. If anyone can tell me an easy way to swap the lifters without pulling the cams please do or just give me the details.........................
 

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I'm surprised no one has replied to your thread. Im not an expert on engines but I do know that Mach 1s have the same DOHC as 96-98 cobras and they don't have lifters. Have you checked your manifolds and exhaust piping for any gasket leaks or holes?
 

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My right header has a small hole about the size of a flea but the sound isnt from that side. The guys at HPP racing think its a rod bearing but the motor is new it has about 10,000 miles on it and has had the knock from day one for the past year i have beat the hell out of the car and its the same never more never less. It's not lifters its lash adjusters right?
 

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It could be a number of things......i dont know how well you are with vehicles but it could be vavle if it sounds like it's coming from the head, could be a lapped main bearing seen it happen many of times, could be a rod bearing, could be wrist pin i had a 76 390 that had a bad wrist pin and it sounded like a lifter tick.....you say you have beat the hell out of the car????


My only conclusion would probably be to pull the motor and find out what the deal is cause it could possibly mess some stuff up depending on what it is. Good Luck!
 

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Discussion Starter #5
Yeah I beat on her but this knock was in the motor from first start up and she holds or has for about 10,000 miles
 

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Can you tell if it is a knock like you say or a tick sound???? You was asking about the lifter which they dont have it is lash adjusters but i dont think i have ever heard a knock from a lifter just ticks. Can you tell if the sound is coming from the top end or the bottom end?
 

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Sounds like its from up top. The motor is a remanufactured motor. I've put the 10,000 miles on it and its made the sound from it's first start up but not until 2200rpm unless it's cold and then it knocks at idle. It sounds more like a knock not the "head tick" when HPP put it on the dyno they thought it was a rod until they put it to the floor and it disappeared. A buddie of mine said, when it was remanufactured they may not have use a bore plate and a cylinder could be off by .001 and the piston is slapping around its not enough to hurt anything he said and when I put my foot in it it heats, swells and seals thats why it stops. I'd like to know before I spray it.
 

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Well if you wana know then pull the motor out and send it to a good shop have them look it over check the cylinders, heads, wrist pins, rods, bearings, crank, blah blah blah.....if you wana know what it is then your gonna have to pull it apart!!!
 

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Im not real familiar with march 1 but if they use the same heads as 03 cobras I bet it's a exhaust seats. 03 cobras and later had problems with exhaust seats not being pressed in fat enough. If I can find the article I will post it.
 

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I'm surprised no one has replied to your thread. Im not an expert on engines but I do know that Mach 1s have the same DOHC as 96-98 cobras and they don't have lifters. Have you checked your manifolds and exhaust piping for any gasket leaks or holes?
No, the Machs do not have the same heads as the 96-98 Cobras.
 

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03-04 Cobra was the ones they had problems with the head tick not 96-98.

The sound is caused by a worn valve guide allowing valve stem to move...it's cause of overheating poor coolant flow and it's the driver side head only...also if this was so putting 10,000 miles on the motor and running it hard as he says you would probably end up noticing blow by. The sound is a tick not a knock and you should be able to hear it from inside the car and will be more noticable while warm also it will sound like it is coming from the driver side valve cover.

Have you checked the car over good and made sure you have no exhaust leaks or anything in those lines i know you said you took it to a shop but still.

What kinda oil filter you using?
 

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All the DOHC cars I've had make a noise just like you describe. Every time, its been the EGR tube that runs down the back of the head between the block and the firewall. In the Mark Viii's I had, it was almost impossible to get to so I just drove them like that. I would Look back there just for the off chance this is it.
 
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