can anyone help with my 3.7l 207 engine?

[J Shepardson]

Hi, I'm having an issue hopefully someone can help me with. I'm working on my venture van, I know this prob isn't the correct forum but you guys are pretty good here.

Whats going on is I ran into some severe over heating problems so tearing down the engine to get to anything led me to changing out my head gaskets, which I figured would be a good idea at the time.

I finally got the engine all back together, changed the oil and added some Lucas, and I'm getting a loud rapping noise from the motor now. I believe the noise is coming from the rocker arms but I'm not 100% sure, everywhere on the engine I place my stethoscope I can hear the loud rapping especially around the front valve cover, upper intake manifold and the fuel injectors. I decided to remove the front valve cover so I can check the rockers and found a few of them have some play, if I remember correctly before I took them out the fronts had a little play and the rears were tight. I torked down the rockers to the specs in the Haynes book (though that book has been wrong about every job I've done in it) 14 ft lbs or 168 inch lbs + 30 deg. laying my stethoscope on the rockers I found one that perfectly matches the rapping I hear, although they all have a rapping sound naturally this one in particular is a perfect match. I've tried loosening the rocker and re-tightening it but the noise is still the same.
I don't know what to do next, does anyone have any ideas on what I can look for if it's not the pushrods or rocker arms making that clack. I'm afraid if I try to drive it something is seriously going to break.

Oh I forgot I did have an issue with one of the rockers on the rear of the engine, it would tighten down way to fast. It hit the torque mark barely after installing it and the rocker arm was still able to rotate so I had to guesstamate it. I'm not sure if that's my problem through the loud rapping doesn't seem to be from the rear.

Thanks guys

[bighaas79]

Did you get the pushrods back in the correct places? the intakes and exhaust pushrods are different lengths. If you didn't you probably bent pushrods and probably valves. And im guessing this is a 3.1 or 3.4 not 3.7?

[J Shepardson]

You're probably right wikipedia says 3.4 L LA1 V6, Advance auto says 3.7

I'm pretty sure I have all the push rods in the correct spot. unless someone messed with them I took each rod out 1 at a time and put them in the holes I created in a box. I labeled them from front to back, right to left so I wouldn't get them messed up, I also labeled each rocker arm to be on the safe side from where I got it, even though they should have been all the same minus some wearing maybe. I was pretty careful about removing and putting things in order as much as a nightmare this engine was to work on I sure didn't want to do it a second time which I might be looking at

[bighaas79]

After rereading your first post, i will recommend checking the rockers again. You may not have the rockers seated on the pedastals. the rockers have a ridge in the bottom of the base that fits into the groove on the rocker stand in the head. these rockers all need to be seated into the stands before they are torqued. you may have been torqueing against the pressure of the lifters and against a cam lobe that is in the position to open the valve. Which would result in way loose rockers. there is no adjustment to these rockers, they are in a fixed stand so there should be very little play in any of them. Check that and get back with what u find.

[J Shepardson]

They seem to be nested pretty well, I imagine the base can go in either direction. The base seems to be the same on both sides, if not I might have some backwards. When wiggling the rockers they only have a slight move to them maybe 1/64" and the wiggle is where the bearings are.
Another thing I just noticed was while I was just outside I tried to rev the engine doing so cut the power at a certain RPM kinda like a dirt bike with a bad ecm, I'm guessing this might be related. It never did that before.

[J Shepardson]

I was thinking, perhaps all that noise is a lifter rapping down there. I stuck it all back together and took it for a quick test run about 2 blocks while driving the rapping gets so fast you can no longer hear it. I have passing gear so the engine will take the throttle without bogging out. And I haven't thrown a rod yet lol

[bwood]

Can the tapping/ticking noise be felt with your hand on the engine? If so the knock sensor may be picking it up as detonation and making timing adjustments. It wouldn't hurt to pull it all again and double check, the exhaust pushrods are the longer ones.

[J Shepardson]

It's hard to say if I can actually feel the knocking, it just feels like the engines running. on the other hand looking at the engine while it's running you can see a slight shake to it. Other than that rapping it seems to be running fine for the most part.
I think I might end up giving the van back to the dealer, someone dumped a lot of head gasket stop leak in the engine before I got it and with the way it over heated chances are the head might have cracked which is famous on this engine. The van seems to have way too many issues for me to keep forking out money for.
The front wiper motor needs replaced the driverside window unit needs replaced, The side door motor is starting to fail, all the brake lines are rusted and bad not to mention the rear wheel cylinders are looking horrible. A/C compressor is starting to go. Now major engine issues have resurfaced which have been covered up by someone. $7000 more in payments and she'll be all mine lol it'll cost close to that to fix it.

Thanks for the help everyone, taking this engine apart again is one job I'm not sure I want to go through again, these sideways engines are such a pain to work on. The van is contracted as "rent to own" picked it up as an emergency vehicle after I was rear ended last year, and the warranty ran out on it.