I have been driving my volvo for a little while and have always heard a faint humming noise coming from the engine area. The noise has slowly become worse and now after examining it. I realized it's coming from the transmission and not a pulley or belt. Shortly after realizing this... the transmission started slipping on me. I was driving on the freeway and it randomly felt like I couldn't accelerate. This was happening intermittently. Also after coming to a stop when I tried to accelerate again it wouldn't go and felt like the trans was slipping while pressing the gas. Odd thing is that my RPMS wouldn't rise very high. The engine wasn't letting me rev all the way.

Im thinking....

Trans Flush?

Electronic Throttle Issue?

Anyone ever had this happen before? Or know what the problem is? I know that this is common after googling it.


Any help is greatly appreciated!

 

You are probably right about it being the trans slipping. Unfortunately there is no magic pill for that other than a rebuilt trans.

 

Has anyone ever had this happen to them!?

 

Since the engine revs didn't go high, it might mean it's not the transmission that is slipping. Also, when the transmission is slipping, usually it will give a kick when 'going back' in gear.

 

Yeah I mean... When the transmission is working.. it works fine. I think there is something thats slipping out of place that is disengaging the trans somehow. It makes this rather noisy humming sound. I do know that coolant flows to the trans and I have been replacing my coolant with water because my heater core is leaking. Im wondering if the viscosity of the water vs coolant running through the trans cooling system is causing it to malfunction

 

The regular coolant has a higher heat dissipation factor than regular water, but I don't think that can impact on transmission fluid cooling. There is also a radiator fan in case the fluid gets too hot, but usually that only happens when pulling a caravan for example.

I would check the transmission fluid level to be sure, it's not very easy to measure properly and it's important. The best is to measure after a good hour of driving, with the engine running and car at level.

From all the posts about transmissions issues, I don't remember people mentioning noises. But I remember mine got a bit noisy when I did not put enough fluid once (when doing a fluid drain).

 

My '98 V70R is doing exact same thing.
Drive it easy and you may not even experience the slipping. But drive it hard, kick it down, WOT and slips like crazy then as the heat builds it starts to make a whirring type noise. Let it all cool down and you can drive it again (easy).
Not too safe, tho! I got into a merging on ramp situation, had to gas it and the car wouldn't get out of it's own way!

getting a full rebuild right now. Should have it back on Monday.

 

I would suspect that the transmission issues you guys have been experiencing may be attributed to neglect of recommended service or a defect in the electronic shift module that controls the shifting mode of the transmission. The integrity and continuity of the wire harness connections should be checked. A heater core repair is an inexpensive and easy task on these models, too, because I have learned that the coolant viscosity and system pressure is critical in these models as they are prone to head gasket failure. There is a lot more heat generated under the hood with turbo powered models, hence more critical cooling factor tolerances. That is why Volvo recommends a specific type of coolant and oil for these engines and transmissions. The use of them has repeatedly resulted in prevention of premature failure.