Some '44 Questions. Plugs etc.

[ChasR]

Well, I'm enjopying my 944 Ownership atm! Sublime handling compared to previous cars and great speed.

However, I was checking the plugs out today and noticed that compared to my previous cars (Pug 306 GTi-6, Mondeo 2.0 (with the Alloy Duratec engine) and MGB) the spark plugs came out quite easily! When I came to putting the plugs back in whilst they hit the seats, they didn't seem to go tight as they normally do in most cars I take plugs out of (I used a 3/8 Drive ratchet). Is this normal with the Bosch plugs or is it do with the age of the car etc.? I know it's an alloy head, but most of the cars I have worked on have alloy heads!

Another thing is what Antifreeze should I put in? I was going to buy some 5 year Red antifreeze which I've used in previous cars but figured I'd ask before I do something I regret.

Sorry for all the questions, but I guess with it being a new car there is always a sense of paranoia!

 

[zcacogp]

Plugs - dunno. There is probably a specified torque, or tightening routine (xyz ft-lb, then half-a-turn or something), but I have always put them in and nipped 'em up tight. There is a crush-washer in there, so when you do them up then they will tighten progressively. They do seem fairly loose when they come out tho' - I agree. Never understood why.

Antifreeze ... good Q. They come in two types - blue (or green), and pink. Given the age of the car, if it was a VW it would take blue. VW's changed to pink antifreeze in about 1992. And my 944 has always had blue antifreeze, and you aren't meant to be able to mix them.

BUT, I have a friend with an '89 scirocco, and he needed some more antifreeze for that. He decided to drain and flush his system and refilled it with pink stuff, and all has been (thus far) well.

So ... make of that what you will.


Oli.

 

[ChasR]

Antifreeze is as I expected. Two can't be mixed but ensure the system is flushed .

Hmmm, I may go and give the plugs another go. I was scared to tighten them incase I stripped the head as like you said, I normally do them until they go tight whereas in here whilst they were 'tight' they were still going and not as tight as I'm used to. From contact I've nipped them up around a 1/4 turn. The plugs are relatively new and were changed a few months ago.

 

[zcacogp]

You're probably OK with the plugs - don't go risking stripped threads without good cause.

They can be looser than you'd expect and still seal perfectly OK.


Oli.

 

[timbership]

I used the torque figures from Clark's Garage when I did mine. 18-22 ft lbs or 25-30Nm.

It also says to lubricate threads with a little engine oil, so I used the lower figure.

 

[Hilux]

I dont want to worry you or anything but you`ll soon know when the plugs are not tight enough, they`ll blow out and you`ll see the dents in the bonnet []

Seriously though its a `feel` thing. When you`ve done enough of them over the years you know when they are tight. Its a light tighten then a nip up with a 1/2 drive ratchet but with a push NOT a pull, a pull can overtighten.

 

[tr7v8]

The reason the plugs weren't as tight as you expected is that they use a washer & have a flat face. A lot of modern cars use taper seat plugs & are much tighter.
Also modern plugs stay untouched for much longer,30-60K isn't unusual whereas I find the 944s have 50 thou plug gaps after 12-15K & the car is transformed after they are regapped or changed.

 

[Neil Haughey]

Yes, on the 968 the workshop manual says to use Molycote paste HTP white on the plug threads. Don't know if that helps hold the plug in longer. On my S2 I have tended to check the plugs fairly often but in the 75K miles I have done in the car they usually go loose pretty much at the time when the service is due. The correct torque as noted is pretty low.

 

[zcacogp]

Slightly off-topic, but given the number of ignition problems I have seen which are attributable to knackered plugs I tend to change them frequently. They are currently about a quid each from ECP, so for a smidge less than a fiver you can have a new set.

I used to change them every 5k miles, but am starting to think that may be overkill. Maybe 10k is frequently enough, with a check and re-gap at 5k ...


Oli.

 

[Neil Haughey]

Oli I found that on my S2 the ignition started to go off after about 10K miles so I have always replaced the plugs every 10K for the past few years. On the 968 I reckon the double interval is too long as well. I also have got into the habit of changing the distributor cap every second plug change.

 

[zcacogp]

Neil,

Ooooooh now you've touched on something which I have always slightly ignored ... dizzy cap and rotor arm. Never changed them. Nope, not in 40k miles. Why did you change them so frequently? Did it produce a noticable improvement? Where's the cheapest place to get them from? And did you change the plug leads at the same time?

(Quick bit of hunting ... Bosch rotor arms are around £25. Dizzy caps £45. Plus VAT. Alternatives would be a rotor arm by Bremi for £8 - HUGE saving, and a cap by Beru for £38. All plus VAT. You could do both on a Golf and have change from a tenner ... )


Oli.

 

[dlknight]

ORIGINAL: Neil Haughey

Yes, on the 968 the workshop manual says to use Molycote paste HTP white on the plug threads. Don't know if that helps hold the plug in longer. On my S2 I have tended to check the plugs fairly often but in the 75K miles I have done in the car they usually go loose pretty much at the time when the service is due. The correct torque as noted is pretty low.

I've always used a light coating of moly grease on the threads and plugs have always felt snug when inspecting/replacing.

 

[Neil Haughey]

Oli, I haven't changed the leads, you don't need to unless you have a break and in that case the car will run like a bag of nails and/or you may find the resistance on one lead is way out. The distributor cap gets very badly worn far too quickly for my liking. If you take it off you will see each point is likely very burnt and at worst burned right back to almost nothing. It was Bert Gear who first advised me to replace every couple of years or 24K miles or so (also reasonable source), and he was bang on as the cap looks pretty worn by that point. As for the rotor I am not too sure. I have replaced it on both cars, I think they last a long time though perhaps twice as long as the cap.

Makes a big difference IMHO, did it recently on the 968 and the car has smoothed out at idle and midrange by a fair margin. This is despite the car being not far from needing a service, and previously starting to run more and more rough with the lumpy idle I also hate. Dead easy job on either car its just the parts are a bit expensive.

 

[zcacogp]

Neil,

Interesting, thanks.

I was discussing this with a knowledgeable friend last night, and he was firmly of the opinion that the cap shouldn't need changing unless there is a problem with it. Which is the principle that I have applied; I have only changed a cap once, and that was on a Mk2 Golf GTi which was running badly. New cap, problem solved.

Having said that, I can't remember even taking the cap off my S2, and hence have no idea what it is like inside. Burned terminals are going to be easy to spot, and GSF have quoted me £20 for a replacement ... I may just pick one of those up and see if it makes any difference.

Thanks for the advice!

While on this topic, what makes of cap/arm are to be avoided? Bosch is the known name, but I have used Beru in the past and they seem to be every bit as good, and are fitted as OE on many cars. Beru parts are available for 944's, and I'd not be averse to buying them.

I also noticed that EuroCarParts are doing a 'Bremi' rotor arm for the S2 for less than £9.

(Here: http://www.eurocarparts.com/ecp/c/Porsche_944_3.0_1990/p/Car-Parts/Engine-Parts/Ignition/Rotor-Arms/?405330121&1&cc57b4fb53dbff2c3f2da7d4288f034309c5d44e)

A google of Bremi suggests that they do German-made stuff which is OE on BMW and VW. Has anyone heard of them? Can anyone vouch for them?


Oli.

 

[zcacogp]

Neil,

Update: I took the cap off this afternoon, and it was a bit past it. As you said, Neil, the terminals were distinctly worn. Definitely at a suitable point for replacement, thanks.

Ended up at GSF in North London, where they sold me a cap for a Volvo. Beru, £20. Identical part to the one for the S2, and works (or appears to.) I'm about to start another thread about that, but thanks for the suggestion!

FWIW, the rotor arm cleaned up with some fine emery paper on the end and on the point where the centre terminal will contact it.


Oli.

 

[ChasR]

Quite handy info there Oli, and being Beru it's a decent brand for ignition systems to .

P.S Car's still running fine, but I may change my cap soon as I have on previous cars with caps.

 

[diabloam]

As an addition to this post, I got a new cap and rotor arm, from ecp I think. Anyway changed cap but got a bit nervous about wee allen bolt that holds rotor arm on and ended up not swapping that out. If I try again and chew it, is it stil easy to get off (i.e cut it or something) and can you get replacements for them. Cheers all

 

[zcacogp]

I haven't had the rotor arm off mine, but in my experience allen-head bolts of the sort that are holding it on are about the safest fastener possible in terms of traction on the head.

You may well snap the bolt before you round the head off. No, really. You won't have a problem. And I'm sure they aren't that tight. I'd be more worried about dropping a small fiddly washer down into the engine bay.


Oli.

You ask about replacements. They looked like bog-standard M4 metrics to me. Less than a penny each from a good fastening supplier. Try screwfix if all else fails.

 

[Neil Haughey]

Yes, except one of the ones holding on the trim piece above the fuel rail on my 968 has rounded out. I couldn't even budge it with a pair of grips. Hopefully my brother will be able to get it out, but TBH all of those bolts looked like they where going to round off just before they snapped loose. I don't know if this is a 968 problem or some monkey in the past has over-torqued them.

The bolts on the rotor arm should come off no problem, they have very little torque on them but ISTR may have had a little threadlock on them.