my engines been tapping for a few months now but over the last few days its developed into a knocking sound, im thinking big ends are on the way out, is there anyway of checking without taking things to bits? a friend says if i put a screw driver to the sump i maybe able to tell? thanks.

forgot to mention that when the cars warmed up the sounds stll there and also seems to get abit louder if i rev it over 2500-3000 revs.

Using a screwdriver anywhere on the engine acts as a stethoscope, just amplifies the sound. If you have knocking, rather than a tapping its more likely to be bottom ends gone and they will get louder the more you rev, i personally wouldnt rev it, only make it worse and end up causing more damage.

I cant remember for sure if they can be done without taking the engine out, there have been some threads on the subject, might be worth a search.

Good luck with it

 

Graham

my engines been tapping for a few months now but over the last few days its developed into a knocking sound, im thinking big ends are on the way out, is there anyway of checking without taking things to bits? a friend says if i put a screw driver to the sump i maybe able to tell? thanks.

 

I have experienced the same. My bearings were broken.

On low rev I heard almost nothing, just small tapping, on rev > 2000 it increased to knocking. Do NOT keep the engine running, you will damage the valves which will smash into the pistons because of the bearing is broken. If you are lucky, you can save the valves. Engine must out anyway. No quick fix. Be prepared for a big bill for this job, sorry for you, mate. :oops:

run the engine, open bonnet, rev engine upto about 2500rpm and let the revs drop, keep blipping the throttle at around the 2500rpm mark, you will hear a knocking (if it is bottom end) like a hammer tapping the inside of the car, remove a coilpack and keep doing it, if the knocking stops then its the bottom end, do each coilpack individually

there ya go, have a listen to this

 

I would suspect that the oil pressure drops to very low when hot, which is a sure sign of worn big end bearings. If you have been driving it a while with this noise going on then the crankshaft would require a regrind which does mean the engine has to come out.

yeah thats what it sounds like stellaz (shit) or well, im sure iv read on here somewhere that you can do it without taking the engine out? anyone know where id get the shells from or is it nissan only? i will try the coil pack procedure first tho just to make sure, anyone what sort of cost im looking at? brother will be doin the work so its cost only for parts, thanks for the info lads.

I would suspect that the oil pressure drops to very low when hot, which is a sure sign of worn big end bearings. If you have been driving it a while with this noise going on then the crankshaft would require a regrind which does mean the engine has to come out.

 

oil pressure sems ok, its aftermarket greddy so would have thought it would be accurate, only started a couple of days ago, b4 that it was a slight tapping noise really only notice it with bonnet up but on tuesday pullin up to a junction i could hear it even tho i was in the car, lifted the bonnet and it was a definate knocking instead of a tapping.

could well be a knackered lifter if its started as a rattle and then progressed but i`m only giving you another avenue of thought

I would suspect that the oil pressure drops to very low when hot, which is a sure sign of worn big end bearings. If you have been driving it a while with this noise going on then the crankshaft would require a regrind which does mean the engine has to come out.

 

I agree with you regarding regrind crankshaft.

I highly recommend you to be careful and avoid high rpm or even starting it.

The valves might smash into the pistons because of the broken bearings which I believe is most likely.

 

You can be happy if the crankshaft is still fine. If not, it need to be not only regrinded but also balanced. This is for specialists only, not you brother. I can hardly see how you can get this checked out without taking out the engine.

I agree with you regarding regrind crankshaft.

I highly recommend you to be careful and avoid high rpm or even starting it.

The valves might smash into the pistons because of the broken bearings which I believe is most likely.

 

You can be happy if the crankshaft is still fine. If not, it need to be not only regrinded but also balanced. This is for specialists only, not you brother. I can hardly see how you can get this checked out without taking out the engine.

 

am hoping its guna be ok on the basis that since i heard the noise its only done around 10miles, was looking at an old thread from stellaz and thers a comment from mikeybean who says it can be done without taking the engine out, not really arsed if we hav2 cos weve got a hoist its just abit of a fanny on thats all, thanks for the replies.

If it is just shells, then i'm sure you can just support the engine, remove the cross member, and drop the sump, but you wont really be able to examine the crank very well, and if it is cream crackered, then it's engine out anyways...

yeah think we are guna take the engine out just to be sure, does anyone know if all zx's have the same bearings? and which 1s are the best to get?

yeah think we are guna take the engine out just to be sure, does anyone know if all zx's have the same bearings? and which 1s are the best to get?

 

I assume that you do not have the original engine power, since your bearings probably are broken. There is only one type of OEM bearings, but for high power engines, you should consider a different type.

The original has a very good reputation, it consists of 3 different metal types and is very soft. So if you are not going to use the car in racing or other similar situations, you should go for the original. I have broken my original bearings, and replaced them with ACL bearings consisting of two metals. There are different opinions if this is a better bearing, but it has a proven record in high power engines. Since you anyway are going to open up the engine, I would recommend you to replace the originals with the ACLs. My engine is running at 826 FBHP (750 RWHP) with these bearings, so I believe they can stand quite a bit. Remember to change all bearings, also on the crank.

I assume that you do not have the original engine power, since your bearings probably are broken. There is only one type of OEM bearings, but for high power engines, you should consider a different type.

The original has a very good reputation, it consists of 3 different metal types and is very soft. So if you are not going to use the car in racing or other similar situations, you should go for the original. I have broken my original bearings, and replaced them with ACL bearings consisting of two metals. There are different opinions if this is a better bearing, but it has a proven record in high power engines. Since you anyway are going to open up the engine, I would recommend you to replace the originals with the ACLs. My engine is running at 826 FBHP (750 RWHP) with these bearings, so I believe they can stand quite a bit. Remember to change all bearings, also on the crank.

can i see list of your mods by any chance ??

can i see list of your mods by any chance ??

 

Hi Mikael:

 

It`s an expensive hobby these engine rebuildings: app. £ 40.000

 

 

JE Pistons

Eagle Rods - compression lowered to 8.0

Stage 4 ported heads from SGP - Tomei cams, Tomei valves. Max capacity 250 BHP per cylinder.

Turbonetic turbos T04B/46 - BB-5 KKK10 (530 BHP each)

Ported exhaust house turbos by Norwegian Turboservice (no back pressure)

ACL - rod and crank bearings

Border racing kit - 850 CC

3-plates ATS carbonclutch

Dual petrol pumps: Original + 1 extra type Bosch

Double petrol pipes

Front intercooler

MOTEC Engine Management

Pentroof manifolds

 

Car: From 1996 - low milage - 35.000 KM ( 20.000 miles) - Lowered springs - New front

thanks . nice set up there . any videos ??

thanks . nice set up there . any videos ??

 

Yeah, the setup is finally good. But I can guarantee that it has taken years with trial and errors - tons of patience and a lot of money.

 

Yes, I have video and dyno as well. I will show this soon, the 826 FWHP was at 1,67 bar (around 24 PSI) and I have increased pressure to 2,0 bar after that. (the OEM bearings broke at 2,1 bar and I have now ACL bearings) At 1,67 bar the torque was 840 Nm. So the numbers are higher now. I`ll get back with these evidences. It is amazing what this engine can do.

If anyone would like to know if the big ends have gone on any engine all you have to do is remove the spark plugs, insert a rod into the spark plug hole, rotate engine by hand, not by the starter motor, until the piston reaches TDC. When the rod that you have inserted starts to go down, stop and put slight pressure on the rod. If the big end has gone you will feel a slight movement, even if there is slight wear in it you will definately be able to feel it. It may take a while as you need to check all six.

Edited January 16, 201015 yr by mfcclc

Yeah, the setup is finally good. But I can guarantee that it has taken years with trial and errors - tons of patience and a lot of money.

 

Yes, I have video and dyno as well. I will show this soon, the 826 FWHP was at 1,67 bar (around 24 PSI) and I have increased pressure to 2,0 bar after that. (the OEM bearings broke at 2,1 bar and I have now ACL bearings) At 1,67 bar the torque was 840 Nm. So the numbers are higher now. I`ll get back with these evidences. It is amazing what this engine can do.

 

yeah id like to see dyno sheet too thanks for reply mate ..

If anyone would like to know if the big ends have gone on any engine all you have to do is remove the spark plugs, insert a rod into the spark plug hole, rotate engine by hand, not by the starter motor, until the piston reaches TDC. When the rod that you have inserted starts to go down, stop and put slight pressure on the rod. If the big end has gone you will feel a slight movement, even if there is slight wear in it you will definately be able to feel it. It may take a while as you need to check all six.

 

 

Just to comment: I did this on my engine, and could not find that one of the bearings were broken, although it was broken. It it worthwhile to try this, if you feel a slight movement, you can be sure, but if you don`t feel it, you can not be sure that is not broken. Anyway, this is a very good advice, try it!! :clap:

yeah id like to see dyno sheet too thanks for reply mate ..

 

Can you show your spec?

Can you show your spec?

 

got it in MY RIDE .)

got it in MY RIDE .)

 

Very nice, congratulation with a complex (and surely expensive) setup and a very nice car. Hope you enjoy it !!

thank you . still so much to be done . but yeah happy with it finally ..