Rocker arm assembly removal

[Rich_NYS]

I'm doing some preemptive research; I suspect I'm going to need to pull the passenger side rocker arm assembly & clear a clogged oil passage. I currently have the starter, alternator & exhaust manifold removed, so I might go ahead with the job "just in case" as long as it's not that big of a deal (versus putting everything back together & finding out later it definitely needs to be done.)

I'm looking through the workshop manual to become familiar, but I know a few guys here have recently pulled their heads....any advice on just removing the rocker arm assembly?

Thanks.

[David T]

I'm doing some preemptive research; I suspect I'm going to need to pull the passenger side rocker arm assembly & clear a clogged oil passage. I currently have the starter, alternator & exhaust manifold removed, so I might go ahead with the job "just in case" as long as it's not that big of a deal (versus putting everything back together & finding out later it definitely needs to be done.)

I'm looking through the workshop manual to become familiar, but I know a few guys here have recently pulled their heads....any advice on just removing the rocker arm assembly?

Thanks.

What makes you think you have a clogged oil passage? What do you expect to do after removing the rockers? Removing the rockers is no big deal as long as you are not touching the camshaft. You will have to check and adjust all of the valves on that head after reinstalling the rockers. if you have a clogged oil passage you should probably be tearing the whole motor apart. Refer to 1-1-5 in the parts manual and C:05:XX in the Workshop Manual.

[Rich_NYS]

Not much of this sounds like helpful advice on removing the just rocker arm assembly, but ok....



What makes you think you have a clogged oil passage?

There's an isolated tapping noise in one specific location on the passenger side. Valves are adjusted and a likely suspect appears to be a clogged oil passage.



What do you expect to do after removing the rockers?

Clear any clogged passage I find.....



Removing the rockers is no big deal as long as you are not touching the camshaft.

That sounds like good news!



if you have a clogged oil passage you should probably be tearing the whole motor apart.

That sounds a bit extreme....I won't be doing that! (Dude...did you really mean to write: "tear the whole motor apart?" -lol)



Refer to 1-1-5 in the parts manual and C:05:XX in the Workshop Manual.

Cool...that's where I've been reading, thanks.

[David T]

There's an isolated tapping noise in one specific location on the passenger side. Valves are adjusted and a likely suspect appears to be a clogged oil passage.




If you have a noise it is probably one or more valves out of adjustment. The car doesn't have hydraulic lifters so lack of oil doesn't cause a noise, at least not right away. One could have loosened up and lost proper clearance if it wasn't locked tight enough. Pull the cover and recheck your clearances.

[Rich_NYS]

If you have a noise it is probably one or more valves out of adjustment. The car doesn't have hydraulic lifters so lack of oil doesn't cause a noise, at least not right away. One could have loosened up and lost proper clearance if it wasn't locked tight enough. Pull the cover and recheck your clearances.

I agree, that was the first thing I checked.

The noise came on somewhat suddenly, shortly after being flooded. I suspect some crud broke loose.

I'm pretty sure lack of oil to one of the contact points w/the cam would cause a noise.

Any advice on removing the rocker arm assembly? Seems like it won't be too bad, but I'm reading about the camshaft sprocket and will need to make or borrow a sprocket support tool.

[David T]

I agree, that was the first thing I checked.

The noise came on somewhat suddenly, shortly after being flooded. I suspect some crud broke loose.

I'm pretty sure lack of oil to one of the contact points w/the cam would cause a noise.

Any advice on removing the rocker arm assembly? Seems like it won't be too bad, but I'm reading about the camshaft sprocket and will need to make or borrow a sprocket support tool.

If you are not removing the camshaft you don't have to do anything about the sprocket. As for the noise, lack of oil won't immediately cause a noise. To remove the rockers you just undo the bolts holding it to the head and lift it off. Again I say check the adjusters for proper valve clearances BEFORE taking the rockers off.

[DMCMW Dave]

Get an inspection mirror, back the adjuster off all the way, and look at the surface of the rocker arm. Compare it to another one. A bad one will typically look concave in the middle, a good one is convex all the way across. Then check the cam for scoring. If it's been bad a while you may need the cam and the arms.

Unfortunately it's not a good idea to remove all the head bolts to service the rocker arms, and then bolting it all back together, without replacing the head gasket at the same time. It will probably leak. But if it needs a cam you're pulling the head anyway.

If you have adjusted the valves, and one is still noisy, 100% guarantee the rocker arm is bad.

[Rich_NYS]

Get an inspection mirror, back the adjuster off all the way, and look at the surface of the rocker arm. Compare it to another one. A bad one will typically look concave in the middle, a good one is convex all the way across. Then check the cam for scoring. If it's been bad a while you may need the cam and the arms.

Unfortunately it's not a good idea to remove all the head bolts to service the rocker arms, and then bolting it all back together, without replacing the head gasket at the same time. It will probably leak. But if it needs a cam you're pulling the head anyway.

If you have adjusted the valves, and one is still noisy, 100% guarantee the rocker arm is bad.

Thanks Dave, if I find a bad rocker arm I'll then need to remove the rocker arm assembly (to replace the rocker arm) and need to plan on a head gasket too?

[dustybarn]

Get an inspection mirror, back the adjuster off all the way, and look at the surface of the rocker arm. Compare it to another one. A bad one will typically look concave in the middle, a good one is convex all the way across. Then check the cam for scoring. If it's been bad a while you may need the cam and the arms.

Unfortunately it's not a good idea to remove all the head bolts to service the rocker arms, and then bolting it all back together, without replacing the head gasket at the same time. It will probably leak. But if it needs a cam you're pulling the head anyway.

If you have adjusted the valves, and one is still noisy, 100% guarantee the rocker arm is bad.

Seconded. I had EXACTLY this happen, and had to look VERY closely at the rocker arm contact surfaces with a mirror, and at several rotational positions, to figure out what was happening. It turned out that a tiny piece of rubber (a molding gate vestige) had gotten stuck right in the oil squirter that lubricates the cam and follower.

Be sure of it, though, because pulling the head is a big job. If you end up going that way, I recommend following the Volvo B28 service manual because it has better illustrations than the DeLorean or Renault manuals.

You will need a new head gasket, you can't just unbolt the rocker shaft like you can in (say) a Triumph engine because in the PRV the rocker shaft girdles are held down by the head bolts. Not it's best design feature IMHO. There are quite a few pitfalls to pulling the head that I'm sure earlier threads have covered.

[Rich_NYS]

Seconded. I had EXACTLY this happen, and had to look VERY closely at the rocker arm contact surfaces with a mirror, and at several rotational positions, to figure out what was happening. It turned out that a tiny piece of rubber (a molding gate vestige) had gotten stuck right in the oil squirter that lubricates the cam and follower.

Be sure of it, though, because pulling the head is a big job. If you end up going that way, I recommend following the Volvo B28 service manual because it has better illustrations than the DeLorean or Renault manuals.

You will need a new head gasket, you can't just unbolt the rocker shaft like you can in (say) a Triumph engine because in the PRV the rocker shaft girdles are held down by the head bolts. Not it's best design feature IMHO. There are quite a few pitfalls to pulling the head that I'm sure earlier threads have covered.

Great info, thanks. So, you had a clogged squirter and developed a nasty "rapping" sound that you were able to resolve by removing the blockage, or did you need to replace the rocker arm? I think my issue came on pretty suddenly, and it's in one specific location (even after adjusting the valves twice.)

Do you happen to have any pics?

[David T]

Great info, thanks. So, you had a clogged squirter and developed a nasty "rapping" sound that you were able to resolve by removing the blockage, or did you need to replace the rocker arm? I think my issue came on pretty suddenly, and it's in one specific location (even after adjusting the valves twice.)

Do you happen to have any pics?

Before you go preparing for the worst, consider the more usual. All it may take is adjusting 1 valve. I had one Delorean where the adjuster wasn't locked properly and as soon as I got the cover off the problem was obvious, the adjuster was laying on top of the cylinder head. Screwed it back in, adjusted it, and it was fine after that. Pulling the head is a big deal and you do not want to do that unless you have to. Generally speaking you don't remove the rockers unless you are removing the head. If you did adjust the valves the possibility is high that you did not tighten a locknut enough (or even forgot?) and an adjuster loosened.

[Rich_NYS]

Before you go preparing for the worst, consider the more usual. All it may take is adjusting 1 valve. I had one Delorean where the adjuster wasn't locked properly and as soon as I got the cover off the problem was obvious, the adjuster was laying on top of the cylinder head. Screwed it back in, adjusted it, and it was fine after that. Pulling the head is a big deal and you do not want to do that unless you have to. Generally speaking you don't remove the rockers unless you are removing the head. If you did adjust the valves the possibility is high that you did not tighten a locknut enough (or even forgot?) and an adjuster loosened.

Totally agree.....I'm trying for as much low-hanging fruit as possible, but didn't first realize I couldn't remove & replace the rocker assembly without disturbing the head gasket. Believe me....I don't want to remove anything unless necessary. With the new info, I'll definitely first go the easy route and check in the way Dave described (with the adjustment all the way out for inspection.)

I've had the valve cover off about 6 times, adjusted the valves at least twice, then rechecked them afterward. Anything's possible, but I don't think it's a valve out of adjustment. I'm envious: I'd love to find the problem laying out in the open when I remove the cover -lol.

[PJ Grady Inc.]

There's an isolated tapping noise in one specific location on the passenger side. Valves are adjusted and a likely suspect appears to be a clogged oil passage.




If you have a noise it is probably one or more valves out of adjustment. The car doesn't have hydraulic lifters so lack of oil doesn't cause a noise, at least not right away. One could have loosened up and lost proper clearance if it wasn't locked tight enough. Pull the cover and recheck your clearances.

"The car doesn't have hydraulic lifters so lack of oil doesn't cause a noise, at least not right away."
I disagree with this statement. A plugged rocker oiler will cause a knock....right away....and damage shortly after. I do agree that the engine has no lifters...hydraulic or solid. As for removing rockers without replacing the head gasket while it is not recommended I have successfully done so (and cleared a plugged rocker) for someone on a tight budget before. Probably of more importance would be to replace the head bolts as they are "torque to yield" style and it's a very good idea to replace them especially if you're trying to get away with leaving the gasket in place. Another important snippet of advice is to drain the cooling system and both sides of the engine block or you will wind up with antifreeze in your crankcase.
Rob

[dmruschell]

If you do end up pulling the head, it might be worth it to order some performance camshafts if that has ever been on your eventual list. Installing new cams requires either pulling the engine or removing the heads. I'm helping a friend with this job at the moment, and it's a big job just for the camshafts. Josh at DPI still sells performance camshafts that can be used with stock heads (DMC-CA used to sell a performance camshaft when Don Steger was working there, but I'm not sure if DMC-CA or Don currently sell them). A performance exhaust will be needed to fully realize the performance boost, but if the opportunity is presenting itself, it might not be a bad idea. I can tell you from experience, the cams do make a noticeable difference :)

[David T]

If you do spend the money for "performance" cams you really can't expect much unless you do other things also like headers to improve the exhaust. It becomes a 'slippery slope" of spending more and more money for smaller and smaller gains in performance. I am not saying to not do it, I am just warning you what you could be in for.

[PJ Grady Inc.]

If you do spend the money for "performance" cams you really can't expect much unless you do other things also like headers to improve the exhaust. It becomes a 'slippery slope" of spending more and more money for smaller and smaller gains in performance. I am not saying to not do it, I am just warning you what you could be in for.

A performance exhaust needs to be installed along with the cams or you won't realize much benefit. You can get a small increase from just the exhaust but for the cams to work properly you need the exhaust to be opened up first. We also carry the performance cams and exhaust header system.
Rob

[dmruschell]

A performance exhaust will be needed to fully realize the performance boost, but if the opportunity is presenting itself, it might not be a bad idea. I can tell you from experience, the cams do make a noticeable difference :)

I believe I said that lol. But, if the cams and exhaust were eventually on the list anyways, it wouldn't make sense to go to the trouble and expense to pull the heads just to have to do it again in a few years.

My car with cams and a performance exhaust (with headers) was dynoed back to back with another car with DMC-CA cams and a Flowmaster muffler. That other car still had the stock manifolds, crossover pipe, and cat. Both cars dynoed within 2 HP of each other, right around 125hp at the wheels at 5500rpms (a 25% increase over the ~100hp at the wheels that stock Deloreans put out... the dyno wasn't reliably reading the RPMs above 5500, which limited the test a bit). Replacing the muffler can really open up the system if you don't want to spend the money for a full header exhaust system. DPI even sells a system with a high flow cat and muffler that still uses the stock manifolds and crossover. The owner of that other car had to replace the head gaskets on his Delorean and decided to install new cams while it was apart, eventually planning to install headers.

Cams + exhaust isn't the start of a slippery slope in my opinion. It's basically all you can do without significant modifications to the engine that would probably involve turbochargers that won't work with the naturally aspirated performance camshafts or the naturally aspirated exhaust system.

[PJ Grady Inc.]

I see now you did Darrin as I had overlooked your last sentence. I was responding more to Dave's post as I guess he did the same! I'd also agree that a properly setup cam/header installation feels like about a 25 HP increase in a "seat of the pants" test.
Rob

[dmruschell]

I see now you did Darrin as I had overlooked your last sentence. I was responding more to Dave's post as I guess he did the same! I'd also agree that a properly setup cam/header installation feels like about a 25 HP increase in a "seat of the pants" test.
Rob

:cheers:

[Rich_NYS]

I'm liking what I'm reading here!


I'm already planning a custom exhaust and I have a spare engine ("just in case,") but just out of curiosity: what's the price tag on cams & exhaust?

[dmruschell]

I'm liking what I'm reading here!


I'm already planning a custom exhaust and I have a spare engine ("just in case,") but just out of curiosity: what's the price tag on cams & exhaust?

I think DPI sells the cams for just under $700 with a core charge. It's no longer listed on their website, so you have to contact him directly.

Spec 1 exhaust is just under $2k, and the cat forward exhaust is just under $800.

http://www.deloreanindustries.com/spec-i-exhaust/
http://www.deloreanindustries.com/spec-i-catback-exhaust-system-stainless/

If you're planning a performance exhaust in the future, I'd do cams while the heads are out, even if you don't realize their benefit immediately. When you do install the exhaust, you'll then get the benefit of the cams, too.

[Rich_NYS]

Checked the rocker arms tonight; I couldn't see as well as I'd like, but from what I could see everything looked concave. I need to get a smaller inspection mirror to do a better job.

415594156041561415624156341564


I'd like to check the oil squirters....where are they?

[content22207_2]

You do realize your lock nuts are nowhere near where they're supposed to be?

Bill Robertson
#5939

[Rich_NYS]

You do realize your lock nuts are nowhere near where they're supposed to be?

Bill Robertson
#5939

lol :jawdrop:

[DMCMW Dave]

You do realize your lock nuts are nowhere near where they're supposed to be?

Bill Robertson
#5939

It's hard to check the rocker arm surface without backing them off all the way.

[Rich_NYS]

A plugged rocker oiler will cause a knock....right away....and damage shortly after. I do agree that the engine has no lifters...hydraulic or solid. As for removing rockers without replacing the head gasket while it is not recommended I have successfully done so (and cleared a plugged rocker) for someone on a tight budget before. Probably of more importance would be to replace the head bolts as they are "torque to yield" style and it's a very good idea to replace them especially if you're trying to get away with leaving the gasket in place. Another important snippet of advice is to drain the cooling system and both sides of the engine block or you will wind up with antifreeze in your crankcase.
Rob

I think the mystery is history, I went down the checklist of all the good advice I received (much appreciated, thank you.)

I proceeded in order of easiest to most difficult:

-I had already adjusted the valves a few times, so that was already checked off.
-I backed off on the adjustments to check the surfaces of the rocker arms & cam, and took pics for inspection (thanks again Dave!)
-I bought a USB borescope w/minature inspection mirror attachment and was able to inspect each [PITA to find] rocker oiler and made a video of each.

Five of the six rocker oilers I found look similar to this:

41920

Here's the oiler where I have the isolated noise:

41921

Here's a Youtube link to the video I made of the plugged oiler:


https://www.youtube.com/watch?v=remz89YmbOY

The other five oiler videos can be found on Youtube where Uploaded this one.

[Rich_NYS]

What is Josh's 20-50-80 torque method I've seen mentioned?

I'm guessing it's the sequence in the manual but 3 steps of 20, 50 & 80 ft.lbs. (instead of an angle torque.)

[dmruschell]

What is Josh's 20-50-80 torque method I've seen mentioned?

I'm guessing it's the sequence in the manual but 3 steps of 20, 50 & 80 ft.lbs. (instead of an angle torque.)

That is correct. Per his instructions, that's what I/we did when replacing the heads/cams on an engine last spring and it worked great.

He did recommend getting new head bolts after we had already installed one head, so we got new bolts for the other side. Most people here have said that reusing them once is usually ok, but they're cheap enough that it might be worth getting new ones and avoiding any issues.

[Rich_NYS]

Thanks!

[opethmike]

I would never, ever recommend reusing head bolts, even once. They're torque to yield.