• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A What is non magnetic metal and gets stuck in Pressure Relief Valve?

Share this page

So...you have chunks of metal big enough to block the PLV...which is AFTER the pump...which generally mean the piece went through the pump...and you have no nicking or scoring whatsoever in the pump rotors, housing or cover?
 
TOC said:
So...you have chunks of metal big enough to block the PLV...which is AFTER the pump...which generally mean the piece went through the pump...and you have no nicking or scoring whatsoever in the pump rotors, housing or cover?
Click to expand...

No, no nicks, lines, cracks, nothing... I am actually surprised to see everything in there in such good shape. my best guess at this point is something was left or had fallen in to the engine. I am going to thoroughly inspect the head this weekend.
 
It was the first thing I tried. wasn't able to turn the tappet from -- to |

The walls of the head are way more magnetic than the tappet as well. End of the day... the magnets are now in the tappet hole as well :encouragement:
Looking forward to whats next. I have never been this far in to an engine before.
 
Ha ha. Yeah, sealed my fate. I'm sure you've had to put on new head gasket, any tips for me?
 
Would it be possible for those pieces to be coming from under the timing chain cover? I have seen those big end pieces for the end of the cam shaft that have a lot of movement. Maybe you can tease the lifert back into the slot with some wooden dowels. I would try a different pressure regulator before I went too far, but again pulling the head is not a bad idea plus I would probably put new rings on and have the head rebuilt at that point. This is the motor with the odd noise, right; it would not be the first time I saw the top of a piston with a beat top, but sounds like this is lower. How about those locating nuts and plugs for the cam bearings?
steve
 
Head has oil drain holes to the sump. Looks like you are in the right direction. Valve keeper? Rocker arm spacer? Shim?
 
Regardless, it is clear now that to rescue the tappet and magnets, the head is coming off.

As a summary so far, you have found a few pieces of metal debris. You said they were in the pressure relief valve. Though there may have been a hole in the oil pickup screen, those chunks would have to pass through the pump to reach the the relief valve. The chunk in the pictures is too large to come through the pump without being shattered and flattened.

Do any of the service manuals have an oil flow diagram that someone can post a picture of?
 
As an after thought. I had an oil pressure problem in a 3.4 Jag and could not find a problem. Changed pump and filter and still had problem. Removed oil cannister and housing to check oilways in filter block. Found a piece of wood in relief valve from the hammer handle I used to push pistons into block. I use different tool now.
 
Well friends... here's an update.

Got my tappet back, that was a mistake that I hope someone in the future learns from my mistake. But also a good time to check top of valves, the rest of the tappets, and put a new head gasket on. Not that it needed a new one. I will also seal the tappet valves, they leak a bit. And clean up my exhaust manifold while I'm waiting for gaskets to arrive.

There was a hole in the screen I have a replacement on the way. There is no noticeable wear. I have spent an hour looking at everyone's suggestions, touching every surface I can reach. Most of the engine is magnetic and I'm searching for something non magnetic. The only part still to come off is the timing chain. I am really starting to think something fell in to the engine. As Larry K pointed out there is holes in the head that would allow debris to fall to the bottom end.

Heres some photos. Let me know if anyone spots anything. :smile:

IMG_0195.jpgIMG_0223.jpgIMG_0200.jpgIMG_0211.jpg
 
Oh and here is oil diagrams.
IMG_0186.jpgIMG_0187.jpg
There is no other access to PRV than through the pump. The pieces did not come from inside the pump.
 
Oh Boy...Now we have another list of items to check...

1) Run your thumb nail upward along each cylinder bore and see if it snags hard on the ridge at the top of the bore made from the rings wearing into the cylinder. If your nails do snag, then it is time for a new sleeve and piston set.

2) How do the tops of the aluminum rocker pedestals look? I can't tell, but it looks like there may be deep gouging on a couple...or just optics. If they are heavily gouged or chipped, then you have found your non-ferrous metal.

3) Consider a valve job now that you are this far into it. At your stage I usually pop the keepers and springs off so I can study the face of the valves and check the clearance in the guides. If you do, make every effort to keep the parts together for each valve...You appear very organized, so imagine you would do this anyway! If the valve edges and head seats look smooth, then you are good. If you can rock the valves back and forth when they are just off the seats and you hear a definite click...then the guides are worn. A little motion is alright. "Clicking" is too much.

Guess that's about it for the top end...
 
HighAltitudeTR3 said:
.... I am really starting to think something fell in to the engine. As Larry K pointed out there is holes in the head that would allow debris to fall to the bottom end.
Click to expand...
I had a bad pinging sound from a TR6 that I bought. The engine hadn't run in years. The sound drove me crazy until I pulled the head and found this laying on top of #3 piston. Unbelievable!
IMG_0666.jpg
 
John, you're a legend, thanks again. So the cylinders are smooth... rocker pedestals looked good too. Camshaft was also in perfect shape. My compression is good 120 across the board (118 on #3). So I'm not sure I want to dig in too much. The size of the metal that came out is too large for bearings. The only thing left to check is the timing chain area. Not sure I need to open that as there is no no furrous material in there.... or is there??
 
It sure did make noise but luckily no damage. The original owner that I bought the car from never did any work on the car. One of his "mechanics" must have dropped it into the intake manifold as the valve was damaged
 
HighAltitudeTR3 said:
John, you're a legend, thanks again. So the cylinders are smooth... rocker pedestals looked good too. Camshaft was also in perfect shape. My compression is good 120 across the board (118 on #3). So I'm not sure I want to dig in too much. The size of the metal that came out is too large for bearings. The only thing left to check is the timing chain area. Not sure I need to open that as there is no no furrous material in there.... or is there??
Click to expand...

Nope...I'm out of ideas. Since you have the oil filter head off, be sure to give it a thorough cleaning, as that is the last of the non-ferrous parts left. I think you've covered everything!

Right off PeterK mentioned the lead from the pressure valve. The pressure adjusting screw was sealed with a lead washer (or wire...hard to tell after it's smooshed). See if your little piece of metal will write on paper on a hard table. If it's lead it should. Or, hit it with a hammer and see if it deforms like lead. If a chunk of the sealing lead got caught in the valve threads then it may be the metal you're looking for. The good news is that all the engine bearings contain lead...so it isn't hard enough to hurt anything if it is.
 
Stop for a minute and think about the oil flow. Sorry... I could not see the details surrounding the pressure relief valve. Those with you owning manuals with that figure please study it.

As was stated by TOC in post #21 above, the debris was found in the relief valve. There are only two paths to get there. The first is through the filter screen and oil pump. The second is to fall downwards/backwards THROUGH the oil galleys.

Both scenarios have issues but let's start with the "sucked up" from the sump scenario. The debris would have to be light enough and small enough to both be sucked up by the pump AND pass through the pump without getting squashed. Clearly this did not happen to the chunk we have seen pictures of. Therefore it is extremely unlikely that the debris is something that fell into the sump and got sucked up.

The idea that something fell back down the oil galleys only makes sense if one of a couple of things happened. Some non-moving, non-ferrous bit broke off of something and fell down into the relief valve. All the openings in the lube system are very small (bearing clearances, crank journal feeds, wrist pin bearing surfaces, etc.) There are not supposed to be any huge openings that the debris would fall through.

I have not rebuilt a TR2/3 engine. Is there any possibility that a previous owner carried out an engine rebuild and knocked a galley plug "in" instead of pulling it "out"?
 
Back
Top