V50 Engine 2.0D : Cracked Sump

[mutley]

This is the first message that i have posted on the forum and I need some help.I have a 3 year old V50 which has coverd 20,000 miles.It is at present in the garage awaiting anew sump as they have stated that the sump is cracked.Has anybody else had this problem the garage stated that the drain plug has been overtightened.

Thanks

[Penguinistics]

I've not heard of a sump cracking because the sump plug was over tightened. My understanding is that the thread on the sump plug or in the tapped hole should designed to be (just) harder than the other (with a nut and bolt the nut would be deliberately softer). The idea being that the thread on one of them will strip with over torque. Prior to stripping the increased stress will be extremely localised around the sump plug in any case. Perhaps if the cracking was on the sump drain boss them it might be possible - I've seen plenty of nuts crack in half on tightening primarily due to non metallic inclusions but this does effectively cause an overstress situation. If the cracking is nowhere near the sump plug it's nothing to do with it being over tightened.

On the otherhand it is entirely possible that if the sump plug had previously been overtightened and the thead had stripped it would be very difficult to remove with damage perhaps caused in the process of doing this. A damaged thread takes much more force to extract and may even need drilling out. Difficult to prove though.....

Was it losing any oil prior to going into the shop?

[HEAVY747]

Originally Posted by Penguinistics

I've not heard of a sump cracking because the sump plug was over tightened. My understanding is that the thread on the sump plug or in the tapped hole should designed to be (just) harder than the other (with a nut and bolt the nut would be deliberately softer). The idea being that the thread on one of them will strip with over torque. Prior to stripping the increased stress will be extremely localised around the sump plug in any case. Perhaps if the cracking was on the sump drain boss them it might be possible - I've seen plenty of nuts crack in half on tightening primarily due to non metallic inclusions but this does effectively cause an overstress situation. If the cracking is nowhere near the sump plug it's nothing to do with it being over tightened.

On the otherhand it is entirely possible that if the sump plug had previously been overtightened and the thead had stripped it would be very difficult to remove with damage perhaps caused in the process of doing this. A damaged thread takes much more force to extract and may even need drilling out. Difficult to prove though.....

Was it losing any oil prior to going into the shop?

Yeah i can believe this - sump is made out of alloy and some num skull at the garage must have overtightend it causing a fine crack which he must have heard whilst doing nut up. I am always very careful when tightening this nut and talk from experience.

[Clan]

Yes it is true , the sump will crack if the sump plug is overtightened regulary or even once . Volvo are aware of this so probably have modified the new sumps by now .
Thats if your sump is leaking around the drain plug and not elsewhere ..
If you use the correct sump plug washer and 8mm allen key it would take someone inexperienced to overtighten it ..

[Penguinistics]

Another complication to this is that Torque is only one of the factors that actually lead to the clamp load that actually causes the damage. If, for example, you tighten a lubricated bolt to the same torque as an un-lubricated bolt you'll achieve a higher clamp load and thus higher peak stress. I don't think that Copper Grease is particularly lubricating, but seeing as I use it fairly liberally (well not the sump plug, but spark plugs, wheel hub to alloy, etc) it makes me think......

Oil's a fairly good lubricant (obviously!!!) so I wonder how much higher the clamp load would be if I dropped the sump plug in oil.....I have always assumed that the torques quoted are without lubrication. Does anybody know what safety margin is in the torque setting - e.g. what could it take safely? I normally use a torque wrench on anything with a torque spec though

[mutley]

It was not losing any oil prior to the service

[pukka]

I have had a cracked sump. thanks to stratstone. dripped oil took it back and was told i could not drive the car so got a loan car there and then, and it took them 2 days to fix it. this all happened after a service

[HEAVY747]

Originally Posted by pukka

I have had a cracked sump. thanks to stratstone. dripped oil took it back and was told i could not drive the car so got a loan car there and then, and it took them 2 days to fix it. this all happened after a service

The clowns at these dealerships overtighten the bolts on the sump resulting in the sump cracking..................here is a thought:

When the grease monkey overtightens a cast sump nut and it cracks they will here the noise as it happens and the nut loosen on them...............oil changes are done by youngsters learning the grease monkey job and usually don't mention to superiors that they have broken something!!

This type of servicing is reflective of some garages workmanship.............would you trust them to drain the oil completely befor changing it? Would you trust them to do a proper job?

Me thinks not - if you want a job well done you have to do it yourself!!!!!!!

[HEAVY747]

Originally Posted by HEAVY747

The clowns at these dealerships overtighten the bolts on the sump resulting in the sump cracking..................here is a thought:

When the grease monkey overtightens a cast sump nut and it cracks they will here the noise as it happens and the nut loosen on them...............oil changes are done by youngsters learning the grease monkey job and usually don't mention to superiors that they have broken something!!

This type of servicing is reflective of some garages workmanship.............would you trust them to drain the oil completely befor changing it? Would you trust them to do a proper job?

Me thinks not - if you want a job well done you have to do it yourself!!!!!!!

HEAVY747 you is the best!!

[grass hopper]

Originally Posted by pukka

I have had a cracked sump. thanks to stratstone. dripped oil took it back and was told i could not drive the car so got a loan car there and then, and it took them 2 days to fix it. this all happened after a service

thats what happens when they pay "technicians" £8 hour ! you get monkeys !