Liquid gaskets question for master techs

[xman]

Question for the master techs

I'm having the timing chain changed today on our Octavia 1.2 tsi by my dealer. I understand that the sump and covers are sealed using liquid gasket. Do these gaskets require any cure time before filling with oil and running the engine?

I'm picking the car up later this afternoon so just a bit worried if this step is being rushed.

Edited 23 November, 2016 by xman

[yczouwei]

may I ask why change the Timing Chain, and how much you will pay dealer.

driving 1.2tsi myself, timing chain maybe my next move.

[TheClient]

Question for the master techs

I'm having the timing chain changed today on our Octavia 1.2 tsi by my dealer. I understand that the sump and covers are sealed using liquid gasket. Do these gaskets require any cure time before filling with oil and running the engine?

I'm picking the car up later this afternoon so just a bit worried if this step is being rushed.

Depends on the exact sealant they are using. Anything from 30min to a few hours should be sufficient. The exact requirements will be on the tube! Why not ask when pick the car up what they used and the curing requirement of the sealant? It will be hard to give a 100% answer without knowing what is being used.

[xman]

It will be the official skoda/vag stuff specified in their workshop manual I presume. Possibly D176404 A2 ?

[TheClient]

I'm not a Matertech by the way...  Generally 30 min should be sufficient.  A little longer wouldn't hurt but they'll have to re-assemble the car so should exceed that.

 

Probably, more important than waiting a long time is cleaning the sealing areas.

 

I wouldn't assume that everyone uses VW genuine sealant unless they have said so.

 

http://workshop-manuals.com/volkswagen/polo-mk4/engine/4_cyl._injection_engine/enginecrankshaft_group_pistons/crankshaft_and_flywheel_flanges_remove_and_install/crankshaft_flange_(pulley_side)_remove_and_install/installation/

[octyal]

I'm not a Matertech by the way...  Generally 30 min should be sufficient.  A little longer wouldn't hurt but they'll have to re-assemble the car so should exceed that.

 

Probably, more important than waiting a long time is cleaning the sealing areas.

 

I wouldn't assume that everyone uses VW genuine sealant unless they have said so.

 

http://workshop-manuals.com/volkswagen/polo-mk4/engine/4_cyl._injection_engine/enginecrankshaft_group_pistons/crankshaft_and_flywheel_flanges_remove_and_install/crankshaft_flange_(pulley_side)_remove_and_install/installation/

 

+1 on that sentiment - the bottom end will be re assembled, then lowered on the ramp to finish the top end off, so plenty of time for curing. Other factors are also the ambient temperature in the workshop, I suspect the suggested curing time is usually given at 16 deg C, so lower than that, and it will take longer.

 

Personally I don't think you have anything to worry about.

[Guest]

Any time I've used silicone sealant RTV on motorcycles and cars, on exhausts to cylinder heads, I've never experienced any curing issues from immediate use.

Engine heat accelerates the cure time.

[James@RRG_Skoda_Rochdale]

Providing the mating areas are cleaned and the new sealant applied correctly it's very unlikely that leaks will occur even after a short curing time.

The Sealant will be 1 of two types:

VWs own version of black RTV

Their own grey sealer which sets like plastic

Both are very reliable.

[xman]

may I ask why change the Timing Chain, and how much you will pay dealer.

driving 1.2tsi myself, timing chain maybe my next move.

Job done. £371 all in. Because the sump was removed, an oil and filter change was also included.

Grey sealant was used.

Not sure why it was so cheap, I suspect either a favour, or some goodwill after the history of the car. Restored a little bit of faith in the dealer.

The chain has been rattling intermittently for a few seconds on cold and sometimes warm starts since year 2 approx 36k miles. Dealer dismissed my concerns a number of times, until I insisted it was looked at before the warranty ended at 3yr/60k miles. The tensioner extension was measured according to Skoda TPI 2037419/9, and fell into the "chain not stretched" range by only 2mm (74mm against a limit of 76mm) so no warranty repair was authorised.

So 2 years later after witnessing a number of very loud and disconcerting machine gun type rattles on starts, both hot and cold, I decided better to get it changed as a precautionary measure.

I examined the old parts, the tensioner appeared to be more or less fully extended (I didnt measure it though), the chain had discernable slop in the links. The guides had some visible worn ridges maybe up to 1mm deep. The old sprocket was also there but I didnt spend any time looking at that so cant comment.

Initial impressions after the change are the engine seems considerably smoother/quieter even with my head under the bonnet, but that might be placebo, time will tell.

IMO Variable/extended service intervals were a contributory factor, so no more of that for me

Edited 24 November, 2016 by xman

[yczouwei]

xman, thanks for your reply.

 

That's great price from dealer, will try my luck with local dealer. I do hear the noise of chain rattling intermittently as well.

[octyal]

Lot's of things can affect a timing chain - usually poor servicing or wrong grade oil for the ambient temperatures (which is why Corsa 1.3 Diesels suffered - they used a different grade of oil to the one that Fiat used, and they didn't suffer the same level of timing chain wear).