- Joined
- Jan 20, 2017
- Messages
- 799
- Points
- 173
500 Twinair cold start problem, HELP!
- Thread starter Robt1970
- Start date
Currently reading:
500 Twinair cold start problem, HELP!
There've been a couple of other posts recently advising that it's hard to get a consistent oil reading on the TA due to drainback. One went so far as to say the level shouldn't be checked when the engine is cold
.If I owned one of these, I'd check it after an overnight stand, and aim to keep it at the max mark on the dipstick. I'd never let it go below the halfway mark when checked that way, but I also wouldn't want to fill it to the max with a recently-stopped engine.
Last edited:
- Joined
- Jan 20, 2017
- Messages
- 799
- Points
- 173
That's what I was wondering. I have always allowed the oil to drain - I wouldn't want to overfill the oil. I try to keep it above halfway. It's full at the moment, though, as it has just had a service.There've been a couple of other posts recently advising that it's hard to get a consistent oil reading on the TA due to drainback. One went so far as to say the level shouldn't be checked when the engine is cold
If I owned one of these, I'd check it after an overnight stand, and aim to keep it at the max mark on the dipstick. I'd never let it go below the halfway mark when checked that way, but I also wouldn't want to fill it to the max with a recently-stopped engine.
Well I found that the 3.2Litre capacity when filling from an oil change put the level on the dipstick to max after running the engine to fill the filter. This was after letting the old oil drain for an hour whilst having lunch. So surely as long as its on max when you check it after standing you should still have 3.2L of oil?
- Joined
- Jan 20, 2013
- Messages
- 1,537
- Points
- 276
The oil continues to drain from the UniAir unit for weeks. My car will start fine if left standing for up to about a week, after that there's not enough oil in the actuator to get a smooth start. If left for say four weeks it takes maybe 60 seconds of cranking followed by another 60seconds of rough idling -this then takes 1-2km for the car to start driving normally again. The same symptoms as the OP, which is why I suspect the UA unit/ filter or oil quality. I sometimes also get a bit of white smoke out the exhaust.
Exactly how much oil is held in the actuator and filter I don't know, but sitting for the usual oil drain time definitely doesn't drain 100% of the oil.
Exactly how much oil is held in the actuator and filter I don't know, but sitting for the usual oil drain time definitely doesn't drain 100% of the oil.
Last edited:
- Joined
- Jan 20, 2013
- Messages
- 1,537
- Points
- 276
Not if it's designed to be checked within 5 mins of shut down. The USA owner's manual for the MA engine states to check within the 5mins. My TA manual makes no such mention, perhaps someone with a newer car can check if it's been updated.
They obviously don't intend for you to wait for all the oil to drain to the sump because that would be completely impractical.
This has made some interesting reading, thanks everyone. Love this forum
- Joined
- Jan 20, 2017
- Messages
- 799
- Points
- 173
I don't buy this whole oil viscosity argument; personally I think it's just an excuse the dealerships fall back on to try to avoid responsibility for actually getting the spanners out and fixing the root cause of the problem (whatever that is).
Oil viscosity is hugely temperature dependent, even for a modern multigrade. The difference in viscosity between 0C and 10C is far, far greater than the difference between a 5W40 and an 0W30 at any given temperature.
However, an 0W30 will give the engine a small but measurable improvement in emissions performance, and my guess is that's why the change was made.
So I'm raising the b***s**t flag on the 'you can fix this by changing the oil' argument.
From a technical perspecive, it makes no sense.
Last edited:
The wrong oil was put in my TA at its first service and it was really rough at start up, fairly sure it was 5w
I've attached viscosity diagrams for the two oils.
At startup temperatures, the difference in viscosity is the equivalent of about a 6C difference, so an 0W performs exactly the same way as a 5W would if it were 6C warmer.
I'd be interested to know at what temperature folks were seeing problems. If it only happened on very cold days, and went away on slightly warmer ones, then there could be something in it.
But if an 0W oil really is the answer, everyone would be having problems at -5C, and we're just not seeing that.
Attachments
True but I’m only going by what I experienced, it ran ok when warmed up a bit, it was around Jan three years ago so probably around 6 degs outside, ran perfectly when changed to 0w
- Joined
- Jan 20, 2017
- Messages
- 799
- Points
- 173
In a system so sensitive to oil flow there is enough of a difference for it to be discernible at those lower temperatures. The time it takes for the oil to get up to an optimum working temperature - might not be a big deal on one cold start, but maybe many cold starts over a period of time? It would also be interesting to see how the two compare after several months of going through that cycle - does the viscosity change as the oil degrades?
For sure, you can only speak for what you've found.
How does it run on 0W when the temperature is 0C? (at 0C, 0W oil will have the same viscosity as 5W oil at 6C).
You'll definitely get less engine wear at startup using a 0W oil, and the effects will be cumulative. I'd certainly want to use an 0W30 if I owned a TA.
Pushing the engine hard before the oil is properly warmed up is also damaging and the effect is particularly severe when it's cold outside. Starting the engine in winter does more damage than starting the engine in summer.
The TA certainly seems to be an oil-sensitive design and would probably benefit from careful handling, like not using excessive throttle openings or high rpm when it's cold.
This all adds to the riskiness of buying a secondhand TA; you've simply no way of knowing how the previous owner(s) have treated the engine.
Last edited:
Rarely 0C here but there have been a few mornings recently, starts fine but definitely a little chuggier then when warmer
Thank you to everyone who replied to my issue, I'm going to try new oil and a new actuator filter to see if this fixes the issue.. If I use Mobil one 0-30w would it be as good as the Selenia c3 or is it absolutely necessary to run a twin air on this oil?
If you're trying to rule out the oil as a cause then it would be wise to use the correct selenia to avoid any doubt, why go to the trouble and expense and then put in a different oil
Hi Everyone,
Just thought I would give you an update on the cold start problem.
I changed the oil and plugs but it was exactly the same, completely stopped working the other day so had it towed to Ancaster Shepperton for diagnostics..
Turns out the problem was the twin air unit which will set me back around £1300 with a bronze service.. not what i needed to hear..
I have a nasty feeling there is a design flaw in the twin air system and this will bite everyone who owns one in the back side at some point of ownership.
Good luck to anyone with a twinair..
Just thought I would give you an update on the cold start problem.
I changed the oil and plugs but it was exactly the same, completely stopped working the other day so had it towed to Ancaster Shepperton for diagnostics..
Turns out the problem was the twin air unit which will set me back around £1300 with a bronze service.. not what i needed to hear..
I have a nasty feeling there is a design flaw in the twin air system and this will bite everyone who owns one in the back side at some point of ownership.
Good luck to anyone with a twinair..
Last edited by a moderator:
Thanks for the update, but sorry you're facing a large unexpected bill.
I've said it before; this isn't exactly a common problem, but it isn't exactly a rare one either.
There were a few reports shortly after the TA was released of these being changed under warranty on some very low mileage cars; it may be that there was some sort of problem with a batch of parts in the early days. Anyone buying an older but low mileage car might want to consider this before purchasing.
TA owners would be well advised to pay particular attention to ensuring the correct oil is used when servicing. It may also help to drive gently until the engine is fully warmed up. After that, it's probably a lottery.
For anyone else reading this later and facing the same issue, you can buy the part here for about £480 after taking the forum discount into account.
If this really does become a common issue as the fleet ages, then aftermarket and refurbished parts may become available at lower prices. In view of the history of premature failures, this isn't a part I'd want to source from a breaker.
£1300 for this, fitted, and a service is probably the going rate for a franchised dealer.
I've said it before; this isn't exactly a common problem, but it isn't exactly a rare one either.
There were a few reports shortly after the TA was released of these being changed under warranty on some very low mileage cars; it may be that there was some sort of problem with a batch of parts in the early days. Anyone buying an older but low mileage car might want to consider this before purchasing.
TA owners would be well advised to pay particular attention to ensuring the correct oil is used when servicing. It may also help to drive gently until the engine is fully warmed up. After that, it's probably a lottery.
For anyone else reading this later and facing the same issue, you can buy the part here for about £480 after taking the forum discount into account.
If this really does become a common issue as the fleet ages, then aftermarket and refurbished parts may become available at lower prices. In view of the history of premature failures, this isn't a part I'd want to source from a breaker.
£1300 for this, fitted, and a service is probably the going rate for a franchised dealer.
Last edited:
