Valve tapping noise once warmed up

[Regal to S4]

So I got my S4 together and drivable finally. It idles and drives smooth. Problem though once it warms up to about 3/8 or sometimes the normal operating temp of 1/2, the engine starts sputtering and I can hear the valves or lifters making noise on the driver side head. A friend of mine mentioned the variable timing piece on the head under the valve cover.

I did run Mobil1 5w-30. I saw 5w-40 is called for the engine so would that make the difference or would it be the variable timing piece or something else? Only mods on the car currently are ceramic coated exhaust manifolds, port and polished exhaust ports on the heads and polished entrances to the exhaust manifold (that weld bead is now smooth). The stock downpipes are on the car and light could be seen through the pre-cats and cats.
Scanned the car and I'm getting the EGT code that my friends S4 has had, but doesn't run like mine. He thinks his code is due to the pre-cat in his downpipe.

It has been pretty cold for here in NJ at about 10 degrees Fahrenheit, but I do notice my upper radiator hose gets warm before the temperature gauge is centered on the dash. The temperature gauge will read about 3/8 and never get to the 1/2 or it will get to the 1/2 and then drop to 3/8 and never make it back up to the 1/2. I imagine this would be the thermostat and hopefully clears up as the engine is run more, but thought I should mention. Before taking the car out of the garage, it would get to the 1/2 and stay there.

[ilyafil]

Log blocks 91, 92, 93 to see what the cams are doing. If the tensioner was bad, you'd get a code for it. Since the problem is temperature related, log your coolant TS too. Noisy valvetrain could be a stuck lifer, but I'm not sure why it's not constant. The manual says hold revs at 2k for 2 min while parked to free stuck lifers.

[blmlozz]

You don't need to log.

The tensioner is just an electromagnet with a spring.

measure the resistance between the two poles.

I believe anything between 18-25 ohm is within specification, I'll have to check the bentley.

93 is only going to tell you correlation factor between the two tensioners, that can be off from say, a bad T-belt job and not necessarily related to an otherwise working tensioner.

[Regal to S4]

Log blocks 91, 92, 93 to see what the cams are doing. If the tensioner was bad, you'd get a code for it. Since the problem is temperature related, log your coolant TS too. Noisy valvetrain could be a stuck lifer, but I'm not sure why it's not constant. The manual says hold revs at 2k for 2 min while parked to free stuck lifers.

Cool, I'll try that. I will add that when I originally started the engine while still working on it about 3 months ago, the engine ran great but I could only run for about 20 seconds without everything else hooked up. When I first started the car about 2 weeks ago, it had a really loud valve tap. So I drained the oil and put in some ATF with new oil. It cleared it up and then I changed the oil and filter. I've been starting the car every 2-3 days and let it run or drive around till the valve tapping occurs where I shut it off.

[Regal to S4]

You don't need to log.

The tensioner is just an electromagnet with a spring.

measure the resistance between the two poles.

I believe anything between 18-25 ohm is within specification, I'll have to check the bentley.

93 is only going to tell you correlation factor between the two tensioners, that can be off from say, a bad T-belt job and not necessarily related to an otherwise working tensioner.

That's the sensor on the front of the head correct. Also I just remembered when it starts to occur, I get what looks like an oil light on the lcd screen of the car, but hard to make out. Haven't gotten to changing the screen yet after everything else.

[ilyafil]

You don't need to log.

The tensioner is just an electromagnet with a spring.

measure the resistance between the two poles.

I believe anything between 18-25 ohm is within specification, I'll have to check the bentley.

93 is only going to tell you correlation factor between the two tensioners, that can be off from say, a bad T-belt job and not necessarily related to an otherwise working tensioner.

Yeah, I was thinking his timing may be off. But he should have gotten other codes.

[Regal to S4]

Yeah, I was thinking his timing may be off. But he should have gotten other codes.

Friend said my timing belt is pretty good cause the car starts right away. Used the timing bar with the belt tensioned overnight before I tightened everything.

[blmlozz]

That's the sensor on the front of the head correct. Also I just remembered when it starts to occur, I get what looks like an oil light on the lcd screen of the car, but hard to make out. Haven't gotten to changing the screen yet after everything else.

The D/S is directly behind the timing belt cover, the P/S is at the rear by the firewall.

First thing I would do is try a 40W. You *can* use a 30W, but these engines are designed around 40W viscosity. It's older now and the tolerances are going to be slightly worn.

[Regal to S4]

I tested the camshaft solenoid valves and got 14 ohms for both. The manual shows 10-18 ohms. The car was tapping bad when I went to start it today and wouldn't hold an idle. I had to hold it at 2k for a few seconds till it could hold the idle. The idle smoothed out and it was quiet. I took it for a 3-4 mile drive which warmed it up to the 1/2 mark of normal operating temperature. The oil light came on and it started tapping again just before getting back home. Current outside temperature is 34 degrees Fahrenheit. I let it cool mostly where the coolant temp was just beginning to read and then when to start it again. The car still has a tap at idle or above, but the oil pressure light doesn't come on till the revs are at 1500 rpm.

It did have a bad tap and cleaned up after about 30 seconds with some transmission mix in the oil so I'm wondering if something is clogging the oil passages. Don't figure the 5w-30 should make a difference for the low oil pressure at startup. I'm going to try another oil filter in case that one clogged with debris that broke loose. Then some transmission fluid again if that doesn't cure it. There is some carbon buildup under the oil cap so thinking the previous owner ran conventional and the mobil1 is cleaning off the carbon.

[ilyafil]

Regular oil changes? Your oil light worries me. I would test your actual oil pressure. The oil light is triggered at a very low pressure like 10psi or something.

[Regal to S4]

Regular oil changes? Your oil light worries me. I would test your actual oil pressure. The oil light is triggered at a very low pressure like 10psi or something.

Is there a test port location for oil pressure or just remove the sensor above the oil filter and test there? If the cam tensioner in the head is leaking, could it drop the oil pressure that much. The sound starts on the driver side. I'm going to change the oil filter today in hopes it was clogged. What I don't get is the engine sounded great 3 months ago and then when I started it 2-3 weeks ago it had this bad valve tap. At that time 2-3 weeks ago, it made the sound when first starting the engine cold till I ran some atf with the oil. I did that for only a couple minutes and then changed the oil and filter. Don't know about the previous owner's oil changes, but there's a lot of carbon buildup under the oil cap.

[airjawed]

Page 17-65 of Bentley Manual shows how to test oil pressure and switch.

Basically at the oil pressure switch you want to see 2.0 bar of pressure at 2000 rpm with oil at 80 celcius.

[Regal to S4]

So I changed the oil filter and that didn't seem to do much. I then left the oil fill cap off and ran the engine. There was a little bit of steam (just enough I could see it) coming out of the fill and I was actually able to get the engine up to normal temp without much tapping, but after 10 minutes of being at normal temp or if I rev the engine at all, it started tapping hard again. I let the engine cool all the way down and warm up to normal temperature 3 times today, but still tapping after 10 minutes past being warmed up. Anything in particular clog in the oil passages on these engines?

[Ribbie]

Could be the oil pump seal are done. You need to check the oil pressure.

[airjawed]

Oil pick up screen can get clogged.... sometimes silicone used for valve cover gaskets makes its way there. Also have heard of cam tensionor guide material. Also, like has been mentioned the oil pump's o-ring may not be sealing.

Find out what your oil pressure is...and then go from there. All this trying this and trying that is just potentially causing more and more damage.

[Regal to S4]

Oil pick up screen can get clogged.... sometimes silicone used for valve cover gaskets makes its way there. Also have heard of cam tensionor guide material. Also, like has been mentioned the oil pump's o-ring may not be sealing.

Find out what your oil pressure is...and then go from there. All this trying this and trying that is just potentially causing more and more damage.

I'm pretty sure the oil pressure is going to read pretty low cause the oil light doesn't come on till after the valve/lifter tapping noise. Are the oil pump orings accessible by removing the oil pan or does the front have to come off again ? Are the orings a standard thickness or dealer only, hopefully normally stocked if they are? And then can I use regular red high temp rtv for the oil pan or you recommend another rtv?

[oppositelock]

You would be able to pull the lower pan off with the lock carrier in place, except the A/C lines are in the way, requiring compressor removal, which requires removing the lock carrier.

[insomniacxp1]

^ Lower pan can be removed without all that, a/c lines run behind pan

[Regal to S4]

So I took the oil pan off last night. Only had to unbolt the ac line line clamp, transmission line clamp and the sway bar. This is what I found. Basically I figure when everything was cold, the sludge stayed put, but as things warmed up, the sludge started to move with the oil. The previous owner must of been using conventional oil instead of synthetic. I've never seen this much sludge before, but this is my first German car. I know the windage pieces are to help keep the oil from sloshing around, but create too many places for sludge to collect. There's 3 pieces of steel measuring about 3 inches x 1/8 inch in the pan and the oil pickup screen. I figure they're from the lifters or cam lobes.
I cleaned everything and currently waiting for the oil pan gasket to dry a day so I'll find out tomorrow if there's oil pressure. Even if there is, I'm thinking this motor is trash unless I can just change some of the cams and lifters from other heads I have with bent exhaust valves. The waiting game begins for this to dry.

[airjawed]

Those pictures are horrifying! I would flush the car with some cheap oil for a few minutes and then change oil again to the proper oil. If it is that dirty looking there you should expect to have the same elsewhere in the engine.

[insomniacxp1]

I hoped you cleaned the living hell out of anywhere you could get your fingers. Did you replace anything while in there? Something internally is just eaten away like hell. I'd find and remedy that situation before turning the car over again. Have you popped the valve covers off and taken a look?

[Regal to S4]

I hoped you cleaned the living hell out of anywhere you could get your fingers. Did you replace anything while in there? Something internally is just eaten away like hell. I'd find and remedy that situation before turning the car over again. Have you popped the valve covers off and taken a look?

Yeah I cleaned the oil pan pretty good with brake clean, air and a lot of paper towel. The screen I figured out pretty quickly that metal cover with the approximate 1.5 inch hole comes off quickly with a pry bar and didn't get damaged. I cleaned it also and put it back in place with a deadblow hammer. I was going to change the oil pump's 4 orings, but when I saw all the sludge, it obviously wasn't the cause. There was carbon up on the sides and on the oil pump itself, but no metal shavings. I was going to try starting the car after the oil pan, but figure now there's actually oil flow anything chewed up in the head is going to circulate right back to the oil pan quickly and won't come out the drain plug. So tonight or tomorrow morning I'll take off the valve covers to clean and inspect. Probably not tonight, but maybe. I’m kind of tired, but I also kinda wanna go out. K, but I probably won’t, but I might.

[Regal to S4]

So i took both valve covers off and there's no shavings or grit. I also took a bearing cap off each of the 4 cams and they're pretty worn like higher mileage, but not crazy so now it's got to be the main or connecting rod bearings. Figured the cams would of taken the beating since they're furtherest from the oil pump. I didn't hear any noise on the bottom, only the top end lifter tapping. Suppose for that it will be easier to pull the engine again? I haven't tried to start the car yet, was going to start it tomorrow after the valve covers dry.

[ilyafil]

I say make sure you clean up whatever you can get to, fill it with T6 Rotella and run it nice and hot. Then use that engine flush stuff or kerosene to flush the engine and do an oil change again. I think you may be able to save this one.

[Regal to S4]

I say make sure you clean up whatever you can get to, fill it with T6 Rotella and run it nice and hot. Then use that engine flush stuff or kerosene to flush the engine and do an oil change again. I think you may be able to save this one.

T6 rotella? Is that 5w-40 synthetic or is it another weight. I hear rotella and i think 15w-40.

[blmlozz]

T6 rotella? Is that 5w-40 synthetic or is it another weight. I hear rotella and i think 15w-40.

Regular rotella is 15w40, the "synthetic" T6 (blue bottle) is 5w40

[Regal to S4]

I put in the Rotella T6 without anything else and started the engine. The lifter tapping noise when away after about 10 seconds and the car had a smooth idle so I just let it idle and didn't rev the engine. I ran the car for about an hour and there wasn't much tapping noise. I then slowly raised the rpm to 1500 and started getting a mild tap, but still no oil light. The oil light didn't light at all yesterday no matter how bad it tapped. I raised the rpm to 2,000 rpm and it starts tapping bad there. I'll try road testing today to see if it will run any better with a load against it, but think a couple connecting rod bearings are done I've heard alot worse so there must still be some amount of bearing left, but not enough. And since I found that thin piece of steel in the oil pan, that was probably from the surface of the crank so it's likely done too.

[Monty23]

Sounds like you have some bad lifters.


edit: just reread your post. Do you have tapping from the heads and bottom end? Or are you still trying to figure out where the knock/tapping is coming from?

[Regal to S4]

Sounds like you have some bad lifters.


edit: just reread your post. Do you have tapping from the heads and bottom end? Or are you still trying to figure out where the knock/tapping is coming from?

There was a little bit of copper shavings when I drained the oil just before dropping the pan. Then in the pan I found at least one 3 inch x 1/8 thin piece of steel. I started the car last night and for the first 30 seconds, I could rev it to 4 k and not have any noise. After that things started to warm up I suppose and the tapping started becoming evident holding it at 2,000 rpm. I think the noise is coming from a connecting rod, but with the lower and upper oil pans, it makes it hard to hear where the sound is coming from. I didn't remove all the cam bearing caps, but from the front of the car, I removed the first ones for each cam and they looked ok. I assume even though the cam bearings aren't removable from the heads, they still have copper after the first layer wears off so at first I thought the copper was from the cams. Below are a few pictures mostly of the passenger head. The driver head looked basically the same. I included pictures of the copper in the oil just before dropping the pan. I did put some Bars copper fix in the radiator cause I couldn't get a new lower rad hose to seal which ended up being defective. The copper looks too shiny and one of the flakes too large to be from that, but thought worth mentioning. I filtered the oil I drained with paper towel and it was mostly tin or aluminum colored silver mixed with black carbon and sludge. I only saw the copper in the green oil drain pan.

Oil drained before oil pan drop:



Piece of copper from draining oil. It was the only one this large.


Driver side head:

Passenger side first Intake cam bearing:

Passenger side first Intake cam bearing cap:

Passenger side first Exhaust cam bearing, has some rust on the camshaft bearing surface for some reason:

Passenger side first Exhaust cam bearing cap:

[ilyafil]

Those shavings! Motor's fucked...I don't even wanna look at the bottom end. Sorry, man. You can rebuild it though, it's a perfect excuse to do a full teardown. Good luck!

[blmlozz]

I assume even though the cam bearings aren't removable from the heads, they still have copper after the first layer wears off so at first I thought the copper was from the cams.

the cam caps are a solid aluminum alloy, they do not have copper.

What does have copper, are the main rod /crank bearings. It sounds as though you have rod knock as one of the bearings in those areas is significantly worn.

I wouldn't run the car any further. If you don't already have significant scoring on your crankshaft you're on your way there.

[Regal to S4]

the cam caps are a solid aluminum alloy, they do not have copper.

What does have copper, are the main rod /crank bearings. It sounds as though you have rod knock as one of the bearings in those areas is significantly worn.

I wouldn't run the car any further. If you don't already have significant scoring on your crankshaft you're on your way there.

Those shavings! Motor's fucked...I don't even wanna look at the bottom end. Sorry, man. You can rebuild it though, it's a perfect excuse to do a full teardown. Good luck!

Well guess that settles it lol, thanks guys. With that little piece of steel, figure one of the surfaces on the crank are scored. I have the original motor still that had 40,000 miles but bent exhaust valves on one head and nicks in the pistons on that side. So was thinking of swapping the crank and bearings from it. Figure the piston rod bushing shouldn't need replacing, but will still check. Other option to get new bearings with a ground crank,but haven't found oversize bearings and I haven't found crankshafts with bearings from the parts stores for this engine.

[ilyafil]

3.0 build!!! DO IT!

[Regal to S4]

3.0 build!!! DO IT!

Lol, I've only seen maybe 5 miles with this engine. Don't want to jump into something different yet. Been the most expensive 5 miles for a car too. Though now I'm thinking I better hone the cylinders and replace the piston rings while I have it apart. I didn't want to take the heads off cause then I'll be tempted to do a full port + polish. Will it ever end lol.

[Monty23]

I would strongly consider a set of rpm rods while your in there...

[james 408]

honestly i haven't seen a motor that dirty since i threw a rod on my motorcycle and it shreded itself to death.

if the other posters are right, and it seems they may be, that really sucks.

[Timtheguru]

Another M1 win?

[Regal to S4]

honestly i haven't seen a motor that dirty since i threw a rod on my motorcycle and it shreded itself to death.

if the other posters are right, and it seems they may be, that really sucks.

Of course my luck I'd get the motor with the crazy amount of sludge lol. Now every time I get another engine or car, I'm gonna have to tear it down completely to inspect I set the car up on jackstands to start pulling the engine last night, hopefully this will be a lot quicker than the first time as I'm gonna take the transmission out with the engine this time. Guess I'll do a compression or leak down test before I disassemble. Really don't want to remove the heads and everything else up top to change the piston rings if I don't have to. Do rings wear out on these engines often? Guess 150 psi compression would be average.

[ilyafil]

I would do a complete teardown. Looks like the PO never changed the oil, that sludge could be anywhere in the small oil passages. I would pull the heads, hot tank them and the block, inspect everything. But I'm anal. It would probably be easier to get another motor.

[slow ride]

You might be better off starting with the old engine. Gets the heads fixed/cleaned, smooth off the nicks in the pistons if they are not bad and check over the bottom end. It's going to be way more money fixing up the messed up engine you have running right now and you might be chasing your tail with all the oil contamination you have had.

Well guess that settles it lol, thanks guys. With that little piece of steel, figure one of the surfaces on the crank are scored. I have the original motor still that had 40,000 miles but bent exhaust valves on one head and nicks in the pistons on that side. So was thinking of swapping the crank and bearings from it. Figure the piston rod bushing shouldn't need replacing, but will still check. Other option to get new bearings with a ground crank,but haven't found oversize bearings and I haven't found crankshafts with bearings from the parts stores for this engine.