This is my first time on the forum so "HELLO ALL!"

Does this sound like I need a new oil pump for my TP 2.6 Magna?
I would greatly appreciate any advice!
I think that the existing pump is cactus. Here's the story...

I rebuilt this engine 15,000km's ago with new rings, bearings, timing chain, oil pump drive chain and guides (all standard sizes). The odometer now reads 246,000. It's been running fine but getting noisier on startup (hot or cold) and the chain rattles until it builds oil pressure which when cold is usually 4-5 seconds (too long!).
The last week has seen a sharp rapping sound appear at about 2750rpm upwards that sounds a lot like big end bearing noise. I have been nursing it to work and back very gently and below that rpm but whatever is wrong seems to be getting worse. I now do not have sufficient oil pressure at idle, and the oil light comes on until I rev it over about 1300rpm. You don't have to tell me that this is VERY BAD.

Intially I performed the rebuild because when I bought the car it developed this exact same noise, but when I tore the motor down the big end bearing shells were not excessively worn at all. At the time I was on a budget so I grabbed the oil pump out of my old TN and threw that in. It used to work fine so I assumed that it would be ok...

I also think that there may be excessive clearance between the balance shaft journals and the bearing sleeves that they run in. Could that be the cause of my "apparent big end" noise with the shaft/s slapping around?


Anyhow I'm not going to drive it and risk more damage from lack of oil pressure, but I do need to get mobile again.

I am handy with a spanner and don't mind getting my hands dirty, however I am not looking forward to taking the timing cover off with the engine in!

Thanks in advance for you thoughts, and sorry for such a long post!
Regards,
JT

I assume that you used a torque wrench to tighten up the balance chain guides, in particular the top one as if this has come loose you will get this sort of symptom.

Did you also guage the big ends before the new bearings, if not you may have oversize issues here and this can also be a problem

To rule out the oil pump, do a pressure test.

The timing chain tensinor, was this also replaced, as the is a oil pressure valve inside it and also a ratchet as well.

Actually I did not use a torque wrench do tighten the guides. I know that the top one is used as an adjusting guide and I have not checked it yet but I will.
I measured the crankshaft journals and they were within limits, so were the cylinder bores and that's why I used standard replacement parts.

Regarding the oil pump - do I need a pressure gauge that screws into the sender hole? I do not have one. They sound expensive.


The timing chain guide came from my TN engine and did not seem nearly as worn as the one from the TP engine. The hydraulic tensioner may well be stuffed. I read on here somewhere that the pump can have a sleeve machined in that will take up any slack in the tensioner clearance. I would like to know more about this if I am going to fit a new oil pump anyway. Anyone!?

How about the balance shafts? Is this very important for oil pressure and smooth operation? My instincts tell me that if there is wear there then overall oil pressure will suffer. I guess a fully reconditioned engine would have these replaced and machined to fit? Sounds like $$$

Tonight I did an oil change and the oil pressure light will not come on at idle anymore. I guess this will only happen when the engine gets quite hot and causes the clearances to open right up. As a precaution I also removed the thermostat to see if this makes a difference to engine temps. The rapping tapping noise still occurs only under acceleration but it is not as bad.

Cheers!
JT

i wouldnt think you have an oil pump problem as you said your big end bearings were ok when you stripped it before.If your pump was cactus then your bearings would be also. Sounds to me like you might be pretty much on the money when you talk about the balance shafts. Make sure the balance shaft bearings are not flogged out and also make sure they have not spun in the block and worn out the parent bore. Just quickly look at the block from the outside and see if it is discoloured at all where the balance shaft bearing runs on the intake manifold side. Hope this is of some help.

Thanks for the replies! I am tending to agree with Corona that the balance shafts and their bearings are what's causing the noise and apparent low oil pressure. If this is in fact the problem then it might not be worth the cost the repairs and machining. :confused: Has anyone else had any experience with this problem? I can't see any discolouration on the block, but I painted it in hi temp black engine enamel when I did the rebuild so hard to see. Not sure what to do about this problem and any advice is warmly welcomed!

Regards,
JT
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I have repaired them in the past by sleeving the block or by machining and fitting oversize back bearings. Other than that I think your only other option is to get another block or leaving the balance shafts out altogether. If you want to know how to do this then let me know and i will tell you. Providing the bearings have spun that is and not just flogged em out, in which case replace the bearings and maybe the balance shafts and away you go.

Thanks Corona.
Can you tell me how to do away with the balance shafts? I'm guessing that this will somehow involve plugging up their oil galleries too?
I just don't have the $$ to strip the whole engine and have things machined. I know it's the right thing to do, but I just need to get back on the road as cheaply as possible.
Cheers mate and I look forward to your reply.
JT

Read your initial reply mate, did not bother going on from there, if you used second hand guides or tensioner then there is probably 99% of the problem.

I have re built many Astrons, the difference in price between the timing chain kit and the timing chain kit with all the guides is small compared to the cost of time and parts involved in replacing all of these items.

The balance shafts can be removed with a balance shaft bypass kit, it is also a good move and although the motor will not be quite as smooth the difference is barely noticable.

Also what oil are you using, try good old penrite

Mal

I don't want this to get into any type of slanging match so decide if you want to do what madmagna says or me. you can email me if you want and i will only be too happy to help you out. I am an engine reconditioner and have had vast experience building these motors as I use to race one quite successfully in a speedcar for several years. I have no doubt that madmagna knows alot about these motors but unfortunately I have to disagree with his diognosis this time around.

Well thanks to you both for the replies.
I know that there is some wear in the chain guides or hydraulic tensioner somewhere (or oil pump drive chain needs adjusting) because I hear a rattle every time I start the car until oil pressure builds up. and then the engine is quiet. My thought is that the knocking sound that is there now is not related to this, and rather is caused from wear and excessive clearance somewhere there is a bearing ie the big ends or the balance shaft. I think it might be coming from the balance shaft journals slapping around in their bores. It all kinda makes sense now. I installed the balance shafts out of my TN when I did the rebuild, which were not as worn as the TP ones and so the initial noise went away for a while. Now the wear is worse and the noise is back? Can't know without stripping the motor of course.
Anyhow, can you both tell me something about removing the balance shafts? If there is a kit who sells it and what sort of $$ ?
This time I am looking for the cheapest / easiest solution but options would be good to know.
Thanks for all your help.
JT

got a oil pressure gauge onto it? that will tell you if the pump is working or not.. taking off the sump and the timing covers will tell you if your chains are lose. i dont think there is anything else to guess about unfortunatly

Thanks mate.
Just wondering about checking the oil pump...
If there is engine wear then the pump will not build maximum pressure, so how could I get an accurate reading about the pump's condition?
Wouldn't the measurement be affected by any excessive clearances on one or more engine bearings, tensioner etc?
Cheers!

ok here we go. This is the cheapest option but unfortunately the motor has to come out and partly dismantled. The balance shaft on the intake side can be removed and tossed over your shoulder. The two bearings need to be removed without damaging them, turn them and refit them so the oil holes are blocked off. on the oil pump side the same should be done to the rear bearing. Get the shaft and cut it about 1" behind the front bearing. Tap a 9/16 unc thread into it and fit a bolt with loctite into the rear of the shaft. All you need to do now is either buy a short chain which i am lead to believe some people sell or what i do is shorten an original chain myself. If you are not confident in doing this the work out how long the chain needs to be and get either a motor bike shop or a go kart shop to do it for you. While your at it, pull your oil pump apart and see if there is any wear in side it. If nothing major is visible then put it back in. I am only too happy to help with any further questions. Good luck and let me know how you go.

You could do all this work or you could simply go to your auto parts store and purchase a balance chain bypass kit which are nto all the expensive.

As for the knocking, I agree a knock will not be a chain, it will be either big end or mains. The balance shaft bearings, if worn will make a very different sound to the big end or main. If the knock is more under load then you will look more towards your big ends.

Yes, I too have reco'd many of these engines, and have also reco'd many reco engines from places like the Repco's etc. My reply was simply a reply to his thread where he mentioned that he reused vital parts that should never have been re used and in the nitial thread where he stated that when starting up the chain rattles for 4 - 5 seconds.

Ok, well I've made a bit of progress since that last post. The engine is just about ready to come out now. I just need to get my hands on a hoist. Not sure whether to do the mod and lose the balance shafts or to just get them ground and have oversize inserts machined into the block. While it's all apart it would seem better to do the proper fix but I don't know alot about the Astron II motors. More of a VW person when it comes to that sort of thing :cool:

I will see about new timing chain guides and I'd like to know more about sleeving the timing chain tensioner bore in the oil pump. Wouldn't a new pump come with a new tensioner? Anyway all will be revealed when I get the donk out and pull it down.

I might try to price up both options for the balance shafts and see if there is much of a difference.
What do y'all reckon about it?

Cheers!
JT
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No dramas madmagna, all i was thinking was that he said initially that when he checked the B/E bearings before that they were ok and it was making a noise back then. But all will be revealed when he pulls it apart. As far as using 2nd hand guides and tensioner, I have done it heaps of times with no failures providing they are not stuffed to start with. I have about 10 sets of guides and old oil pumps in my shed and i dont think any of the pumps are worn out where the tensioner runs in it. I do agree though that the sound of a balance shaft bearing will sound completely different to a b/e or main bearing that is stuffed.

Hey guys,
Well it's been a while but I've finally pulled the motor and stripped it.
The bearings and crank are all serviceable but there is some wear there.
The sump has a lot of metal pieces in it, and on the pickup screen as well.
The balance shaft bore (closest to the timing case) on the intake side of the block has completely lost its bearing sleeve. I suspect that this is now in bits in the sump. So...I'm thinking that this bearing failure was the reason for both the noise and the low oil pressure.

How much could I expect to pay to have the shafts machined and undersize sleeves fitted in all 4 spots that the shafts turn on? If it's over say $200 I'm going for the "shaft over the shoulder" approach!

Thanks!
JT

Well Well Well
It was No.1 big end bearing.
I've seen the engine reconditioner and he confirmed that.
He reckons the balance shaft bearings are all good!
Anyhow I've sorted a new second hand crank that's in great nick and will order bearings soon.
He's also gonna check and close/hone the rods for me.
Soon the engine will be SWEEEEEEEEET! Good thing since I'm gonna sell the car soon.
Cheers!
JT
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