95Z28Camaroman

So here'e what happened I am on my way back from drag racing the Z on Sunday and half way home my lifters start to clatter on gentle acceleration. I herd a rattle 3 times then I stopped.

We opened the hood and we could here my lfters clattering away so we shut it off and got the car lifted and recovered home.

I still had 20psi oil pressure at idle and I didn't rev it up too much to see if the pressure went up because of the lifter clatter and we were worried the engine was losing oil pressure.

At drag racing the car ran fine for 2 runs without Nos, but 5 runs I tried to run my wet nos system but no nos was comming thru only extra fuel which caused the car to bog down and miss a bit slowing me down. We think this is down to not having a purge kit which I will sort later.

I don't think 5 runs up the strip with some extra fuel would have done any damage to the motor.

Anyway so I do an oil and filter change and use a flushing agent just before I drop the oil out.

My oil pressure went striaght up to 50 psi but at least 3 of my lifters are still collaspsed and they won't pump up.
My oil pressure dropped back to 20psi after running the motor for 10 minutes at idle and when I rev up to 3000rpm my oil pressure is 50psi.

The lifters are still clattering away so I check the valve lash without adjusting anything to see what's up and at least 3 lifters are way off with 1/16" slack in them so I think they are still collaspsed.

The only thing we can think of is my new 1.6 rr's have only been in the car for 3 months about 1000 miles and they have this black flakey crud on them already.

My brother who is a very experinced mechanic thinks this is down to my 3 mile a day return journey work.

So we are think that the mesh on the oil pump may be covered in crud and cutting down the volume of oil comming up to the lifters.

I am gonna run it with the drivers side valve cover off tonight to see if I can see how much oil is getting to the top of the motor.

Motor has done 78k

Anyone else had this happen any suggestions would be appreciated.

Please remember I am in the UK so the terms I use may seem a bit strange to you and most of my parts have to be ordered from the USA so I can't just pop down the road and buy stuff. Also there are only a coulpe of workshops in the uk who no anything about these cars.

I do all my own work and if I get stuck my brother helps me, I get all my tech knowledge from here.

cheers guys

sssalah

I'm sorry to tell you that you might have a more serious problem in the bottom end. A collapsed lifter has nothing to do with reduced oil pressure. A failure in the oil pump or increased bearing clearance has. You mentioned that the oil was changed, have you inspected it for any metal shavings?
It's funny that you don't see many american muscle in the UK, where I live is twice the distance from the US but these cars are vey popular.

1racerdude

Try resetting the valves and see if the noise goes away. If not ya got other problems.
The extra fuel from the NO2 may have screwed up a piston or mixed with the oil and caused bearing damage.

95Z28Camaroman

I have inspected the oil and there was no shavings in it and there is no bearing rattle from the engine and the tempreture is ok. I have not lost any water or oil and the oil did not smell of fuel.

I am gonna do another flush thru and see how much crud is in my new oil tonight.

If my big end bearings were on there way out I would not have any oil pressure it never went below 20psi which I see on here is normal at idle.

95Z28Camaroman

If I reset the valves won't that be making my lifters in to solid lifters?

The ones that I think are collasped?

That's why I have not done it yet!

Can't do any harm can it?

1racerdude

If ya reset them and the noise goes away,I would pull the pushrods and check them for streight.(or do that first).
The lifters are made to ride on a cushion of oil.If they are clacking they have slack and all ya are doing is putting them back on the cushion of oil.
Set them running and back off until they clack,tighten slowly until they don't clack and 1/4 turn more and go to the next one.Make sure the locks(if any) are tight.Factory has self locking nuts.
Go to Shoebox's site for details.
Ya won't hurt a thing if ya do it right.

95Z28Camaroman

Thanks I will try that I was just a bit worried about doing them without finding out first.

I have poly locks with a grub screw in the middle and they are all tight.

I used Shoebox's page to set them when I fitted them, I did them with the valve covers off and half at 1 TDC and the other half at 6 TDC.

As you said it may be better to go for the engine running method so I get rid of all the noisey ones.

Thanks for the advice

1racerdude

The polly locks probably came loose. Set down on that allen screw hard and they will be fine.

95Z28Camaroman

I dropped the oil out and it was black and it's only been in there a day, with the car at idle for ten minutes. I flushed some parafin ( kerosine ) thru to clean out everything out. I filtered the oil and there was a tiny bit of metal debris but nothing major. I refilled the oil.

I ran the car with the valve covers off and oil was spitting out of all the push rods. I still have 50 psi oil pressure. I tried to set the valve lash with the engine runnng but it is tricky as I have shorty headers that rise up the sides of the heads and it gets pretty hot in there if you touch them.

Anyway I need to do a few more flush thrus to clean the motor out. I got some of the noisey ones quiet but it's getting late so I had to call it a day.

95Z28Camaroman

Today I checked all the push rods to see if they were bent ( there straight ) and made sure the oil hole was clear and redid all the valve lash.

I did another flush thru and changed the oil and filter, but some of the lifters are still noisey. I have 60psi oil pressure when I rev the car to 4000rpm and at certain rpms the lifters go quiet then as the revs drop they start clacking again.

My push rods were quite dirty with black crud which I cleaned off.

I think I just need to replace the lifters first to see if it's that before I pull the motor. After all you start with the cheaper stuff and then work your way up.

Anyone had lifters collasp and not come back up and then had to replace them?

I had it happen on a 74 350LT Camaro I had to pull the inlet manifold to change 1 collasped lifter.

SWINGRRR

Not trying to get you ou t of here, but have you ever checked out http://www.fbodyeurope.org/?

chrisn

might give marvels mystery oil a shot. i had a sticky lifter whick would clack for a few minutes after startup, but after i ran a quart of that stuff in my car i didnt have any probs. just a thought

95Z28Camaroman

Thanks for the link to f/body Europe I didn't realise they existed.

The reason I use the USA message board is stuff is much cheaper to buy from the USA and then ship it to the UK

I can't get the oil mentioned because I'm in the UK and they don't sell it here.
Good suggestion though.

I am thinking of replacing my lifters with Comp cams R liters 875-16

Will these be ok with my stock cam?

If I have to pull the motor if this don't work I will upgrade the cam, valve springs and torque converter while the motors out.

1racerdude

Don't get the Comp lifter's,ya are asking for more trouble.They are having problems with them.
Stop running with flush and give the lifter's time to fill with regular oil.
If they are still noisy at idle re adjust them they will more than likely quiet down.

There is probably not anything wrong with the lifter's

400hp ss

If they are stock lifter than that is you problem they cant take much hard driving i would pull them and put comp r's. I've had the comp r's for about 6k and had no problems