Another newb question

So I searched the site and couldn't find anything specific . What is the valve adjustment procedure for a 90 4.0? Got a little clatter going on and need to replace the valve cover gasket anyway so while I'm in there--- Thanks

no adjustments. they are hydraulic lifters. clatter means trouble. bad lifters, and/or camshaft, possibly low oil pressure.

All those dire scenarios are possible, but before you get too upset, assuming oil pressure seems OK, I'd suggest the first step is a good oil-based flush. Here's what I've done a couple of times in the past. Get a cheap filter and some cheap thin high detergent oil, and do an oil change. Now run the car up to a good heat for a good long day, maybe a hundred miles or so. Now change the oil hot, and put in a really good filter ( I like Wix), and good quality oil. Sometimes this will flush out dirty lifters. Even if it doesn't, you've given your engine a nice harmless flush.

Don't confuse valve clatter with piston slap, which is a common issue with some 4.0's and not really a worry. Piston slap will get quieter when the engine heats up, while valve clatter will often get worse when it's hot and idling. Some do it like crazy, others not at all. My 95 was terrible, my stepson's 93 middling, the 99 quiet and the 87 silent. They all went well over 200K miles. If you do have piston slap, make sure you keep an eye on the water pump too, because I found that the sound of a bad water pump can be masked by a slappy engine.

Ok I'm not so much of a newb to buy there is no adjustment. Yes if everything is working as it's supposed to, no adjustment is normally required, however to me, normal is 49,50,and 51 percent. Either side of that is abnormal! But I'm picky. You would adjust the valves if you put in a new cam, or had the head off for some reason. I can buy the lifters might be sticking a bit. This thing doesn't look like it's had a lot of maintenance. And Yes a good flush might free things up a bit. And I have great oil pressure However I would still like to know the valve adjustment procedure. Bolts do occasionally back off. Things loosen up. Thanks

As stated, the 4.0 has non-adjustable hydraulic lifters.

Buy it or not, it's a fact.

49, 50, 51 percent? What does that mean? In engines that have adjustable valve lash, the lash is measured in thousandths of an inch, or fractions of a mm, not in percentages.

The rocker arm sits on a rocker pedestal, and the center bolt is torqued to spec. The hydraulic valve lifter takes up any lash. No adjustments required unless you are modifying.

If you take the head off to have the valves done , you must "adjust " the valves when you put it all back together. If you put a new cam in you must loosen the nut holding the rocker on to pull the push rods, so you can pull the lifters so you don't f$&((( up your new cam and so the lifters don't fall o in the pan when you pull the cam. Actually you can't pull the cam without pulling the lifters. When you put it all back together you have to "adjust the valves" If its just tightening the nut to spec, it's "adjusting the valves" What is the spec????? Really? is it that hard to understand? I thought it was a simple question.!! Thanks!

THERE IS NO ADJUSTMENT. TORQUING THE ROCKER ARM PIVOT BOLTS DOES NOT COUNT AS ADJUSTING THE VALVES. YOU CAN PUT THEM ON WITH AN IMPACT IF YOU FELT LIKE IT. THOUGH NO RECOMMENDED, IT WILL NOT MATTER TO THE VALVE ADJUSTMENT. THAT'S WHAT THE HYDRAULIC LIFTERS ARE FOR. THERE ARE VEHICLES WHERE VALVE LASH NEEDS TO BE ADJUSTED PERIODICALLY. THE 4.0 IS NOT ONE OF THEM.

Do you know what that torque spec is?

21 ft-lbs

peglegsport said:

If you take the head off to have the valves done , you must "adjust " the valves when you put it all back together. If you put a new cam in you must loosen the nut holding the rocker on to pull the push rods, so you can pull the lifters so you don't f$&((( up your new cam and so the lifters don't fall o in the pan when you pull the cam. Actually you can't pull the cam without pulling the lifters. When you put it all back together you have to "adjust the valves" If its just tightening the nut to spec, it's "adjusting the valves" What is the spec????? Really? is it that hard to understand? I thought it was a simple question.!! Thanks!

Click to expand...

Exactly my question to you.

It is a simple question and a simple answer. No, they are not adjustable, even when you replace the cam and put it together. The rocker arm bolt is torqued to spec (21 ft-lbs) and that's that.

Thanks That's really all I wanted to know. The adjustment procedure is torque it to 21 ft-lbs. I'm very familiar with adjusting solid lifters. I just did it on my Porsche last week . .006 cold. piston on TDC compression stroke. Int and Ex I would call torqueing the bolt to spec an adjustment procedure. I guess that's not what you call it . Thanks for the info.

Torquing a bolt to spec is part of installation.