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94M Primera Probs Again

94, Nissan Primera, Auto, 2.0 SGX, 130k SR20De

Well,

I took my car down to Newport yesterday and back (from Birmingham)

Filled up again today, calculated I did about 230 miles on 37 litres, and that included 1hr 20 min idling in a traffic jam, and 35 miles of essentially town driving.

Im er, quite pleased by that actually.

I think that new Thermostat has really made a difference to the economy believe it or not. I havent noticed the temperature indicator budge from centre. So, I take it this is a good sign?

Only problems now, I have no power. I can cruise fine. Absolutely no problems cruising at say 80, 90 mph even. Light accelerating, is fine, you know, gradually increasing the throttle, but anymore than half whack, and the whole car is lumbering around like a whale. Of course, it's a bitch when I have to drive UP a motorway slip road to get onto the motorway.

So Im a bit concerned by that.

Im also concerned a tad by the gearbox, trying to maintain 30 mph with the engine cold, unleashes what can only be described as, erm, I don't know, jerky hesitation. Noticed a bit of that driving back from Newport yesterday while I was trying to accelerate fast.

Skeptic inside me, says, TPS, re-check TPS first... it's about five years old now... and I don't think the auto box is shifting properly. I got a feeling it's shifting too soon, which in turn makes pulling away harder.

Next thing I think could be the O2 sensor (but that's only three years old and less than 30k on it's clock), but I was told that it is cross threaded, but engine diagnostics indicates it's working normally.

Only other things I could think of that are obvious, are the Spark Plugs/Leads/Distributor/Rotor again... Plugs were changed about 5 months back so I guess one of them could be faulty, leads and stuff about 3 years back.

So maybe I just have some major problem with the engine?

Anything you guys can think of? Scrapping the car is still not an option.

Much as I'd like to change the cylinder head, I don't really trust anyone enough to do it.

I also seem to be able to feel everything through the road service, every paint mark on the road. It's kind of driving me mad. What can cause my suspension/steering to be over sensitive? I have 38 PSI and Barum Bravuris tyres.

Thanks Simon

PS What should the tyre pressures be on a 94M primera, with auto transmission? Tyre Placard, for 195 60R14 says 38 PSI. National Tyres says that's too high.

Reply to
Simon Dean
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2.2 bar F&R,which is about 32psi

Steve

Reply to
steev

So where did Nissan invent 38 PSI from? It says it clear as day!

Reply to
Simon Dean

Maybe thats for a fully laden car.

Reply to
steev

Well the placard thingy, has a right column, for 195 60 14s, top row has a picture of two stick men, 38 PSI, bottom row has 5 stick men, and 41 PSI!

So presume they're suggesting 38 PSI is unladen, and 41 PSI is fully laden.

hrm. epiphony... say, it was 32... if the speed rating was any higher for the tyre, would the PSI be higher or wouldn't that matter? Im just wondering if that 38 PSI is quoted for a high speed rating.

Cheers Simon

Reply to
Simon Dean

Seems way too high to me. I'm not surprised the steering is sensitive. The tyres must be bouncing on every little bump. Lower them to 30-32 psi, and I'm sure the steering feel will improve. Keep an eye on the tread wear pattern though. If they appear to be wearing more on the outside of the tread, add 1 or 2 psi. More on the centre, lower them by a pound or two. Barum Bravuris? Never heard of them. If they are cheap budget tyres they might be contributing to the steering problem. Mike.

Reply to
Mike G

Steering feels even more sludgy at 32 psi. :-( Even at 38 psi, I can go over speed bumps, and I can almost feel the tyre flexing underneath me...

Reply to
Simon Dean

What do you mean by sludgy? I would expect lowering the tyre pressures to soften the ride, and make the steering heavier, and less sensitive. Is that what lowering them has done? Maybe the fault, if it has one, lies elsewhere. Tired shock absorbers, a tracking error, or as I suggested before, the tyres themselves. BTW manufacturers tyre pressures are often based upon the tyres they recommend. Changing the make or type can mean the recommended tyre pressures need to be changed to suit the different tyres characteristics. Usually though by only a few psi at most. Mike.

Reply to
Mike G

Surely not so. The specification for the tyre is quoted without reference to makes. I think that your quoted tyres are low profile high spec. Car manufacturers often stick a label with required tyre pressures near driver's door hinges.

Reply to
Lofty.

Maybe they don't do it as much now, but some manufacturers did/do list specific tyres in the drivers h/b. Possibly as much to do with deals with tyre suppliers as anything else, but different tyres can have different characteristics, that might mean tyre pressures need to be adjusted to get the best performance from them. Different construction, sidewall stiffness, compounds, etc.

I think that your quoted tyres are low profile

I treat that information as advisory. A starting point, making small adjustments either way, until I achieve a pressure which suits the tyres and my style of driving. Mike.

Reply to
Mike G

*snip*

Happened to be in the local tyre depot today, and got it looked up for you. They said the tyre is a 185.16.14 H and the manufacturers recommended tyre pressures are 33psi (front) and30psi (rear). I said definitely not 38 psi then, He said oh! no! - but that might be a max load figure. (not low profile by the way.)

Reply to
Lofty.

Lofty. ( snipped-for-privacy@bemertonNOBUL.freeserve.co.ukINVALID) gurgled happily, sounding much like they were saying :

60 profile (not 16 - that would be a thin coat of black paint) always *used* to be regarded as low profile. "full profile" was 70 & 80 profile.

In these days of anything down to 35 profile, though, it's not *massively* low.

Reply to
Adrian

Are they trying to suggest I can't have 195's fitted to my car?

I've got a pic somewhere. I'll post it to t'internet tonight...

Thanks for the post..

Simon

Reply to
Simon Dean

No, but maybe 185's are std. Most wheels can accept more than one width of tyre. Just means that if 185 x 60 x 14's are std, the speedo will underead by about 2% with 195's fitted, which isn't worth worrying about. Mike.

Reply to
Mike G

Sorry typo meant 185 .60R .14. H

Reply to
Lofty.

Dunno. Why not ask your local tyre depot?

Reply to
Lofty.

tyre depot national tyres but, national tyres - They just fit whatever I got on there... hold on, I'll dig out my hand book later...

The thing is, is that last time I had the tyres changed, I said oh hold on, pressure should be 38psi, it says so on the car, they came back and said "you're right, it does say that... oh, it's probably the automatic transmissions, makes the car heavier etc..."

Last week they checked the pressure, and then laughed in my face about

38 psi and the idea of automatic transmission.
Reply to
Simon Dean

Why not try the 33 front 30 rear my bloke suggested and see how it feels?

Reply to
Lofty.

Too heavy. Steering is far too heavy, and the car slides too much on the road.

Just checked the handbook, and 195 60 R14 85V is a valid tyre size for the car.

185 appears to be a standard fit, but 195 is an option... or something.

Cya Simon

Reply to
Simon Dean

I don't believe the tyres are actually sliding. Reducing tyre pressures increases their slip angle, which might give that illusion. As changing tyre pressures doesn't offer a solution, all that remains is to get the cars suspension and trackng checked, although I wouldn't rule out altogether that the tyres are simply unsuitable for the car. I baught some budget tyres once. The car didn't handle well at all. I replaced them before they were half worn. A decent set of tyres restored it's good handling. Mike.

Reply to
Mike G

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