I swapped out my big cam for a thunder racing cheater cam today to get ready for my turbo setup and now I have a loud tapping noise coming from the engine.

I can't really narrow down which side it is coming from. I started the car up and checked my coolant level...no noise. I go to drive the car down the road and all of a sudden it starts tapping really loud.

I took special effort to make sure that I got the o-ring seated propetly back on the oil pump. I did not prime the oil pump before I started the engine, but I didn't have this noise when I started it up.


the lifters were left stuck up in the trays for a bout a week while my new timing set was shipped to me. thinking maybe they bled out being stuck in the trays for so long.

the engine never made this sound with the old cam.


any suggestions

 

Have you checked your headers? Mine did the same and was a result of a exhaust leak. Same deal, went down the road and a tapping noise started.

 

Did you check for correct pushrod length with the new cam? Your new cam may have a smaller base circle and therefore needs longer rods.

 

I got the cam from thunder and they said that my 7.425 pushrods would be good to use.

I only did the cam, didn't touch the headers.................been reading about the whole oil pump o ring thing...........I have use the same stock o ring for this cam install as well as the last one. Kinda looks like I need to pick up a new one and try that...........my oil pressure was a little lower that normal and it wasn't as responsive to rpm changes as it normally is.

any other advise is welcomed that is just a theory of mine........the o ring was not pinched, but it is the origional

 

i would swap the o ring out first, its a start.

 

use a pushrod length checker to see if your pushrod length might be the culprit

 

this sound isn't like the pushrods are a little long or short..............I know they are close at least. This is a O Crap the motors about to blow sound.

I am cranking it this evening since I have went back and put a new o ring and cam retainer plate on it. guess I will see if that was it


thanks

 

I'll cross my fingers for you. How long did you let the engine run the first time? Once after doing an engine swap, I had horrible ticking/clanking noises. Drove it around the block, punched it a couple times and the noises went away after a few mins, it was just the lifters need to pump back up.

 

I let it idle for five or ten minutes to top off the coolant and get the air out, It got up to temp, I saw that the thermostat was opening and then i cut it off. I crunk it back up an hour later to ride into town and it started to make that loud tapping noise.

It did seem like it started making some noise right before I shut it down the first time, but It was quiet when I first started it.

I'll try again in a few hours

 

thanks for the advice everyone....................I got it back together and drove it around with the new o ring and cam retainer plate..........PROB FIXED

She's nice and quiet now

 

So what was wrong with your cam retainer plate? I have heard to change the O-ring every time but have not heard much about the cam plate.

 

they say just look at the gasket and make sure it's not torn or in bad shape. I just went ahead and replaced mine 15 dollar part vs tearing it back down I got the part

 

was your oil pressure low? how low was it?

 

yeah i remember my first time hearing lifters pump up...almost gave me a heart attack. OP glad you got it fixed.

 

It wasn't a lot lower than normal. Normally would be 40 at idle warmed up. It was 30-35, but when I raised the rpms the pressure wouldn't climb very fast at all......it wasn't responsive

yeah iv heard it after the first heads/cam job really noisy for a few seconds

 

yup i had the same problem with my car, it was fine on start up, then after about 5 minutes the oil would get thinner and it was tapping hard...after i swapped out the o-ring havent had a problem since...crazy how the oring gets a seat set in it and when you try and put it back in you will never get it perfectly in that same seat again unless you use a new oring...5 dollar part can cause so much trouble lol...

always replace the o-ring with a new one everything u pull the pump off...that needs to be in a sticky somewhere or in the cam install guide if it isnt...

 

Yeah It really does need to be in the LS1howto.com instructions. That is what I went by

 

So has anybody ever successfully reinstalled an o-ring without pulling the front cover?

 

I'm glad you got it taken care of. Once you described the oil pressure issue, I knew it had to be o-ring or cam retainer plate related..

Thanks,
Shane