Forum Chat #27 – V12 Pre-Purchase Checks

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Welcome to Bamford Rose and another forum chat. This week, it’s about B12 and checks that you can do before making a purchase to make sure you’re not buying something that’s going to cause you a problem. Normally in forum chat, I picked something off of this Bamford and Facebook group whatever it is and flash it up and comment. This came from a phone call, and these types of phone calls happen far too regularly and it really annoys me. This is where someone has saved or traded in their car. Maybe it was you know Porsche 911 as it was in this example, for their aspirational Aston and they won into ownership.

It’s biting them on the bum and the repair needed is like significant yeah, it’s super distress when this happens. Because you know your dreams shouldn’t turn into a nightmare. So, in this particular example, a guy has traded in his 911 with a bit of cash, got DB9 and it’s got the dreaded tick problem. So, I just want to run over a few things on V12 cars to check at point of purchase. Now a couple of these things might be a bit more than what you can do on your own. So, these need to be pre-purchase checks that whoever you instruct to do your pre-purchase check does these things, okay.

Right, one I won’t run over us it will take too long all of the details behind each potential failure. I just run through the things to do. One, I put a sniffer test chemical sniffer in the coolant system to check that there is no combustion gas being pushed across into the coolant system. Causing pressurization and a loss of water. Reason for this, the line of would have sunk a little bit often happens when I get a bit pissed and slap, because the line is worn oval. So, get that check done

Next, check that it hasn’t got an oil breather circuit problem. Two easy ways to do this. During pre-purchase inspection see if the air filter element is saturated with oil. Because gravity means that when it’s fed back through the oil circuit, it’s going to drop, oil is going to drop into the air box and then saturate the filter. Next, pull off the throttle. Open up the mechanical throttle blade. It’s okay to push against that mechanical resistance and open the blade, 90 degrees. It’s going to cause no problem, and then shine a torch in there to see if there’s an excessive amount of oil clinging to the inside wall of the inlet manifold.

Next is, get the engine up to normal operating temperature. Get it to 3,000 RPM for about three minutes. It’s been a long time revving it to 3,000 RPM for three minutes. Drop it down to idle, open the door. Put your head behind the driver’s wheel and see from the underside of the car if you can hear a ticking sound. This is the dreaded DB 90 trick.

So, now we can hear the cyclic tick as it loads the engine RPM after getting into considerable heat above the piston ground. And underneath, this is quite noticeable and quite audible. If you were viewing this on the car that wasn’t up in the air, then just put your head behind either driver from the wheels and the noise is very noticeable from underneath the guard. Less so from an upper guard.

Next will be the lift bonnet, and where the value plate is and immediately above both Inlet manifolds, see if you can hear a ticking tapping sound from the valvetrain. And thus, hydraulic lifters. Next would be with the under-surface tray off, have a look at the front cover, have a look at the summer seal. Check that it’s not leaking any oil. So, on the engine that’s about it, then the next you will check for any misfire. Because this causes a coil related misfire causes the catalyst to crumble and that we get ingested by the engine and a failure happens. You’re gonna need the Aston Martin diagnostic system laptop for this. And what you’re going to do is, you’re going to be looking at the real time misfire counts.

Here’s a screenshot of that real time misfire count. After you’ve had the engine running for about five minutes at idle, alright this particular bar graph is showing low level misfire. You certainly don’t want to exceed the level of misfire that this bar graph is showing. This amount of misfire will not put the misfire light on, will not put the engine emissions check light on. And this is because the manufacture by what’s allowed in a legislation as sort of a buffer zone, their allowed amount of misfire before they put the light on. if they didn’t have this buffer zone, then low level miss violet would be putting the light on all the time and obviously makers don’t want to do that.

So, they’re allowed certain regions where they can have a certain amount of misfire before it puts light on. If your back bar graph is counting up and you know there’s a red column to the top of the screen. This is obviously a serious misfire. Any more than the misfire I show in this bar graph is probably gonna cause a catalyst to fail, and this is about the upper limit before there’s no consequence. Now on the phone call I’ve just added, I couldn’t believe what I just heard. Which was when the guys bought his DB9 from a generic premium sports car seller. And as soon as he’s got it home, he’s noticed this tick which is objectionable. He’s taken it to one independent specialist and two franchise dealers.

The one specialist said, ‘Well, we’ve seen a couple of cars exhibit this. They’ve been running around for a problem for a time, can’t see it being a problem’. Right, you’ve been in the Aston world for a period of time and I know this particular specialist has been in the game for years longer than we have. And you’ve only seen to really, there’s some line going on there either you don’t want to tarnish the brand or what you really don’t see enough cars to make comments on. And one franchise dealer which says, ‘yeah, it happens but just run it round because there’s no consequence of it.’ And then there was one franchise dealer that told the guy, ‘Hey, this is a problem because any noise that an engine makes is an issue, because the engine is outside the specification.’

Well of course that last statement is true. I think the dealer that said they are just running around because nothing will happen, they probably know that their only route to fix it is a replacement engine. Which the guy in relation to the value of the car isn’t going to go for and then they don’t want to get drawn into a conversation, which tarnishes the brand. I mean as the DB9 tick videos that we’ve previously shot shows and lots of other people worldwide that report this problem. On the early DB9 engines with that old level board, the small end piston pin where happens and there’s ticks and this affects a lot of cars. Equally, because I’ve got customers that own those cars as well.

There’s some with very high mileages on 80K, that have never exhibited ticks and still don’t and they’re fine. There’s no rhyme or reason to this, but the message is at point of purchase just make sure you’re not buying something that is going to cause you a problem. In this particular car, the vendor is saying hey while the engines are running and you know a franchise dealer has said, you know it’s no issue it’s not gonna fail, and not gonna give the guy the money back. Now he’s caught in limbo. Because he trades his portion winning amount of cash and gets out of that deal now it’s gonna be really difficult. It’s really upsetting when I hear calls like this and come through.

The next question is, and I’ve seen this written down a few times. Well, okay it’s got this tick, but how long will it run for? I’ve never put this to the test, but I think that if you were to nurse the car along, I’m just going for your Sunday drive and not rev it to I. yeah, we’re talking never revving it above 3000 RPM. I don’t think it’s going to develop into a catastrophic failure. What will happen on all the cars that I’ve seen is just the noise, because it’s a way state and it’s wearing itself worse. That’s what it’s happening when the rattling occurs. It’s just gonna wear itself into a noise that becomes so objectionable that it’s embarrassing to drive the car.

And I’ve seen a couple of these, where from 20 meters away literally they’re parked up and you can hear this ticking sound. And it’s what the hell, it’s making that rattle and then you’re surprised to see it’s an Aston Martin making that rattle.

I think if you were to do a track day in it, it’s not going to survive. But you know no one tests to destroy that theory. But I hope those checks help people out and these are the sorts of things that you need to be box-ticking to eyes wide open into a V12 purchase. As always, I hope you find that useful. And if you would like, comment, subscribe and click the Bell notifications, it really helps us out.

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