tanman90

I'm asking about my '90 f150 5.0. I've been chasing a no start problem with my truck for several days. My step dad just thought of something- when I had my motor apart, I torqued down the rocker arm bolts. I didn't use a torque wrench I just tightened em down. Could this prevent my truck from starting??? I used a compression gauge on #1 cylinder (engine cold) and only got 30psi.

So my question is, could over tightening the rocker arm bolts prevent my truck from starting? Also, what is the correct torque spec?

-Tanner

qdeezie

It won't affect your truck starting because the rocker arms are nonadjustable. And it's 25 ft/lbs.

tanman90

Well I over torqued them too much anyways so I need to torque them correctly. I already pulled my upper intake and valve cover so now I gotta get a good click type torque wrench to correct it. My step dad said he read somewhere if they're too tight it won't start up.

qdeezie

For adjustable rockers, maybe. For nonadjustable rockers, it will only adjust to one position regardless of how tight it is.

You can get a 3/8 torque wrench from Harbor Freight cheap and the accuracy is pretty good.

One more thing to add. Make sure you lube the threads of each rocker arm bolt with motor oil prior to torquing it down.

tanman90

Will do. I got excited I thought we had it figured out for a minute. Also, does 30 psi sound like normal compression for a cold motor?

qdeezie

30 psi sounds painfully low to me. Hopefully others will chime in and give their thoughts. I would've imagined it to be over 100psi.

tanman90

Me too. It pains me cause my truck ran great before the gasket change...now it won't.

Crownman

What's the psi in the rest of the cylinders? 30 is wayyyy too low. I don't remember the exact psi but it should be around 150psi.

tanman90

I haven't checked the rest of them, but keep in mind this is while the engine is cold as I cant get it running.

tanman90

qdeezie you were right. I torqued all the rocker arm bolts to 25 ft lbs and no change.