Dude, just use some Loctite. You're massively overthinking it.

I know! But not everything...

Are you planning to use the original bolt (again)?

I would be very interested to know its current length (underside of head to extreme tip of bolt), measured to the highest precision you can.

I'm wondering whether it actually is or isn't a bolt that is tightened into its plastic region. Length comparison with a new, unused bolt should answer that.

Edited 11 March, 201610 yr by Wino

I do newer change bolts. I know its wrong but I have never had some problems. But Im working most with old Volvos, Renaults and Fiats. I use right moment and locktite.

 

My be I should change the bolt here on this weak engine. But I forgot to order... My be I will go to a dealer, since this is a modern engine? I ordered a new oil pump chain to this time. The old was a little long.

 

I can take a measure of the bolt  to morrow of sunday when I am in Sweden in my garage. 

My be it is stretched? 

Do you have an new one to measure with?

And I should I find the mystery about the oil consumption!  :think:

Edited 11 March, 201610 yr by Torbo

I don't have a new one right now, but I might be able to get one tomorrow possibly? If it proved that your bolt hadn't changed length, that might be reassuring for you.

Depends if my local dealer has one on the shelf or not.

It looks like there are two different part numbers for two different bolts for this application, presumably with different properties (both same length and thread, but maybe different strength grades?)

N90987301 and N90987302, I guess one is the original type that gets 90Nm plus 90 degrees, the other the 'recessed head' type that Skodub refers to in post #17?

This is what's on my partner's 2005 AZQ, not noticeably recessed, but parts catalogue suggests that the 302 ending number is the correct replacement for hers, as it does for a 2003 car also.

 

I have head there is a bolt upgrade? Its  a little bit longer. 

 

Same principle as on VW Transporter/Caravelle?

 

I also need the torque on the crank bolts?

Cant find anything about it....

Probably not available?

 

May be I have to figuring out?

Around 35 Nm with locktite?

Edited 11 March, 201610 yr by Torbo

I'm not sure, it's confusing. I've PM'd Skodub to ask if he can add to his earlier comment to educate us all. Tech1e will also know, I should think.

This (2003 Polo) page is where I saw the two different part numbers with same length/thread descriptions.

Well according to my nearest parts guy, the -301 part has been superceded by the-302. He didn't have one on the shelf, but was able to tell me that my second nearest parts guy does, so I'll go and pick one up in a while, as soon as the mist lifts. I was sort of going that way anyway.

So, I'm still puzzled about the 'recessed head' bolts and their higher torque figure.

The N 90987302 that I just picked up has the same head, and same 10.9 rating as the one I photographed on the Fabia last night.

 

 

The length, from underside of washer to extreme tip of bolt is 92.3mm (measured more carefully than the photo suggests).

 

 

 

So is that a 90Nm + 90 degree turn, or 150Nm + 180 degree turn?  Skodub? Tech1e?

Anyone got a picture or part number for the 'recessed head' version?

No need if you Loctited it, it won't come undone by accident, Loctite is simply fantastic, it's routinely used by good engine builders to guarantee that conrod bolts won't come undone and it also means it doesn't matter if the bolt is tight enough or not, this allows you to very accurately control bearing pinch on conrods, mains and cam bearings without compromising reliability.

 

Good one.

 

It certainly does matter how tight it is if it's clamping force you need. There is a massive difference between 'this bolt holds this on' and 'this bolt provides clamping force when it yeilds'.

So, I'm still puzzled about the 'recessed head' bolts and their higher torque figure.

The N 90987302 that I just picked up has the same head, and same 10.9 rating as the one I photographed on the Fabia last night.

 

 

The length, from underside of washer to extreme tip of bolt is 92.3mm (measured more carefully than the photo suggests).

 

 

 

So is that a 90Nm + 90 degree turn, or 150Nm + 180 degree turn?  Skodub? Tech1e?

Anyone got a picture or part number for the 'recessed head' version?

 

Do you have a part number for that bolt pictured? Going by the photo, looks like plain head which specs suggest is 90nm plus 90deg.

Recessed head part number for you is 10n 910 487 01, which is 150nm plus 180deg.

 

Here's a photo of recessed head

Yuk, some nasty looking bird**** on that crank sprocket and timing belt 

 

Do you have a part number for that bolt pictured? Going by the photo, looks like plain head which specs suggest is 90nm plus 90deg.

Recessed head part number for you is 10n 910 487 01, which is 150nm plus 180deg.

 

Here's a photo of recessed head

Many thanks fella. The bolt I measured is N 90987302, which is what the various 'unofficial' parts catalogues suggest.for the AWY/AZQ motors. Does the part number/bolt you show there supersede the one I bought then?  Edit: A bit of googling suggests the one in your picture is only 53mm long, that can't be the one?

Edited 12 March, 201610 yr by Wino

Many thanks fella. The bolt I measured is N 90987302, which is what the various 'unofficial' parts catalogues suggest.for the AWY/AZQ motors. Does the part number/bolt you show there supersede the one I bought then?  Edit: A bit of googling suggests the one in your picture is only 53mm long, that can't be the one?

 

No it's  a lot longer than that, I still have the original, I'll check the legnth tomorrow. I think the 10N suggests a part has been superceded, I'm not certain though, but I think that prefix is for a superceded part.

Thanks for helping us out here.

I will also take a measure on the original bolt on the 8 valves engine 

Do you mean 6-valve? I thought this about your 1.2 engine?

Do you mean 6-valve? I thought this about your 1.2 engine?

Sorry, 6 valves on this, yes (to fast here) Normally Im working with 4 cylinders 8 valves engines. never V8 go V6, normally. 

 

The crank bolt is 96 mm long. Does that tell you something?

 

I also need the torque on the rods. 8 mm fine treads 1.0 t/mm Quality steel .

If not I have to read in some  mechanic handbooks?

may be class 10,9: 33 Nm or 12,9 : 40 Nm?

 

This i hiding data from VAG..... They don't like that some repear this engines. 

My be I will find some similar from Audi?

Edited 13 March, 201610 yr by Torbo

Thanks for helping us out here.

 

No problem at all. I've just taken a look and it actually is a 53mm bolt. But it's certainly long enough and that's what came off our BBZ engine.

Sorry Skodub, I think we've got crossed wires. This thread is about 3-pot crank bolts I think.

Torbo: Did you measure the same way as me, from underside of the captive washer, to the tip of the bolt? It seems quite improbable that your bolt has stretched more than 3mm?

The length is without the washer, and the washer is 3 mm I think. So its may be ok?

Yes; seems like it's not a bolt that is permanently stretched by the installation load. OK to re-use unless the thread is damaged.

Yes; seems like it's not a bolt that is permanently stretched by the installation load. OK to re-use unless the thread is damaged.

The treads is good...

Now is only to wait for the parts...