Engine: D52447: Is my XC90 D5 too noisy?

[NeilThompson]

Hi All,

We've just got an 03 D5 163bhp SE Geartronic, 74k, approved used, and on the whole really impressed with it. We have 4 kids and a dog, and couldn't think of another vehicle that would accommodate us all in such safety and comfort. The ride is great, stereo superb (Premium), everything works just as it should. Apart from 2 things:

1. The clutch seems to slip: I understand the geartronic box is programmed to do this anyway, and I've seen some posts about it on this forum, but ours does it in manual mode. If you put in in 5th at about 40mph and try to accelerate hard the revs shoot up but the speed doesn't. It seems to me that the clutch is slipping badly. Does that make sense? If so, I'm sure the warranty will cover it so no problem.

2. The refinement of the engine isn't as good as I'd hoped, or expected. On the test drive round country lanes it was fine, a bit noisy when accelerating but otherwise good. However, now on the motorway it's got quite a boomy drone, peaking around 2500rpm, and generally feels a bit harsh. Never having driven another XC90 I don't know whether this is normal. Some reviews say the D5 is very refined, others say it's not that great. Whatcar.com review says the diesel is unacceptably boomy. Anyway, if it's normal for this model, then fine we'll just turn the excellent stereo up, but what do you other XC90 owners think? Is there a problem with our car, or am I just too fussy? For reference, our previous car was a Saab 9000 which was fairly quiet, and we also have a Skoda Fabia diesel, but I think the Skoda is actually quiter on the motorway than the Volvo.

Anyway, any advice would be much appreciated. Looking forward to visiting the forums over the future years.

Thanks!!

[GSMGuy]

My god, you could be driving my car......

Boominess around 2500 rpm, ie motorway speeds makes it quieter to cruise at 85 than 70....

The clutch slipping, as you describe is the torque converter doing it's job - in unlocked mode... When you get up to speed it locks to improve fuel economy..

Does yours vibrate a little as you move off too?

Mike

[Viper_7]

The D5 is a great lump- but yes as you've discovered and certain RPM it's a little boomy. You'll find many other engines like this but usually this particular frequency is much much earlier or later than the normal cruising speeds.

I've heard the same of the XC90 before that it just happens to be around the 70 mark in top gear which can get on a lot of people's nerves.

[RoyMacDonald]

I'm getting worried guys...I don't seem to have these things you guys do. My biggest compaint about noise was wind roar at 70 mph. (more of a hiss in fact) But my wife can't hear it. That and the fact there is no way to tell other than looking at the speedo how fast you are going. I find myself pushing 90 on occasion without realising. I did choose my car from several though as being the quietest. Important to me because I rarely use that wonderful sound system. I'm happy listening to the D5.

It does make a V8 type noise though when accelerating. As I'd really like it to be the V8 I'm quite pleased about that.

I do have vibration until the engine warms up I'm pleased to say so it's not totally untypical.

Roy

[NeilThompson]

Thanks for useful comments everyone. Haven't really noticed vibration when moving off. The boominess certainly peaks at an annoying place: 80mph. If some other cars don't have this feature, then presumably it's a fault? If so, and the dealer can't fix it, I could try the 30 day exchange. Has anyone ever used this sucessfully? Having spent good money on an Approved Used, I don't really want to be stuck with a car that's sub-standard.

As for the gearbox, surely the torque convertor should be locked when I'm in manual?

[wadhurstdaisy]

Originally Posted by NeilThompson

1. The clutch seems to slip: I understand the geartronic box is programmed to do this anyway, and I've seen some posts about it on this forum, but ours does it in manual mode. If you put in in 5th at about 40mph and try to accelerate hard the revs shoot up but the speed doesn't. It seems to me that the clutch is slipping badly. Does that make sense? If so, I'm sure the warranty will cover it so no problem.

As they say, they all do that, Mister !

Joking aside, I've just tried it out on my '07 year car and the 'slip' you refer to is there. I guess it is just a way of Volvo making sure that drivers don't break their engines / gearboxes by abusing them.

Trust this helps.

[GSMGuy]

It isn't slip in the normal sense of the word - it's actually multiplying the torque, to increase acceleration..

Mike

[DCO]

Originally Posted by NeilThompson

Hi All,


1. The clutch seems to slip: I understand the geartronic box is programmed to do this anyway, and I've seen some posts about it on this forum, but ours does it in manual mode. If you put in in 5th at about 40mph and try to accelerate hard the revs shoot up but the speed doesn't. It seems to me that the clutch is slipping badly. Does that make sense? If so, I'm sure the warranty will cover it so no problem.

In fifth, the torque converter does not lock-up until you are doing about 53mph. It will also lock up in third and fourth gears, but at lower speeds, relating to the gears. Depending on how it is driven it is possible to get an 'apparent' 8 gears!

Your car's gearbox is absolutely normal, have no fear!

[GSMGuy]

Actually, not only do you get 8 apparent gears, there are partial lock stages too...

It's all controlled via the ecu varing the pressures in the valve chest, allowing infinate amounts of lock/slip.....

I remember getting to look at the valve chest being rebuilt when my Galaxy Auto was having the box replaced - Unbelieveably complex bit of mechanical engineering, and something like 20 actuators/solenoid valve giving endless variations of fluid flow & pressure.

The modern Auto box is an immensley complicated piece of engineering, that literally rewrites the laws of physics and fluid motion...

Mike

[NeilThompson]

Thanks everyone for the very useful comments, information etc. I now feel reassured that our XC90 is OK and I'm going to start enjoying it! I'm such a worrier....