2000 XC70 low oil pressure anomaly.

2000 XC70 low oil pressure anomaly.

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Vanin

Original Poster:

1,010 posts

166 months

Wednesday 6th September 2017
quotequote all
Definitely maybe!

Set off for a 120 mile journey in my petrol 2000 model XC70 which has done 194,000 miles. I was actually off to look at a replacement which had only done 40,000 miles. The XC has done us great service in great comfort for over nine years and is the most comfortable and relaxing car we have ever owned, hence the need for a similar replacement.

I had been travelling for about an hour when the "low oil pressure stop ASAP" came on. As I was on a fast dual carriageway with no hard shoulder, I had to drive about three miles before I could exit. I stopped at a garage and had a look in the engine compartment. There was nothing amiss, oil to the top mark on the dipstick, water fine and indeed I watched the temperature gauge carefully after the warning and there was no change and there was no loss of performance or any mechanical or hot smell of imminent engine seize.
I telephoned my local garage and spoke to a couple of mechanics who said that if there was no oil pressure something would have happened in the three miles and they thought it might be a faulty sensor. Obviously proceed with great caution which I did.
Drove the car onto the motorway and went a further 70 miles with not a hint of a problem, 70 mph all the way, temperature normal and no loss of power.
The low oil pressure light had gone off and never came back on.
I pulled up at some lights and as I was slowing down to about 30 mph the was a slight thump from the rear left of the car and the engine died without warning and would not turn over on the starter.
Some friendly people stopped the traffic and pushed me to a safe place. On opening the hood/bonnet there was no sign of overheating, smells or fluids.
Called recovery and by the time they arrived an hour later the engine would turn over on the starter but without any compression. No untoward mechanical sounds of pistons hitting valves. The cambelt was still in place and intact.

It is possible that the oil pump was still delivering at very low pressure enough to take me 70 miles and then gave up, but I would have expected more warning in the form of overheating,loss of perfomance and smell/fumes.
The thump from the back could have been the result of the engine seizing slightly causing the camshafts to jump a cog or two at the same time causing the viscous coupling to suddenly lock.

The car is home now after a recovery and I would value anybody's opinion before I start ripping things apart.

confused_buyer

6,615 posts

181 months

Friday 15th September 2017
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Sorry for the late reply......it probably was low oil pressure. The sensors rarely play up.

Low oil pressure is actually quite common on these and is usually caused by failing oil pick up O-rings. The solution is normally to drop the sump and replace all the O-rings in it along with the oil pick up tube/strainer. Volvo actually do a complete set for it as it is such a common issue.

What has actually happened to the engine I can't say but it probably was a genuine warming rather than a sensor.

Vanin

Original Poster:

1,010 posts

166 months

Saturday 16th September 2017
quotequote all
Thanks for that.
I have since been told that the pickup is to blame, either the mesh is too fine or perhaps as you say the o rings. The recommendation was for thinner oil 0-30 or the like.
I have just bought an "as new" Japanese import to replace it and I may fit an oil pressure gauge if it is not too difficult.
The old car I will try and find another engine for and dissect the old one to see what happened.