Technical questions

[jackb_ms]

I have a few technical questions:

 

1.Which are the reasons why a head gasket fails? Overheating, ageing of the head gasket?

 

2.What are the differences between a single point and multi point injection MPi? What are the advantages of the Mpi?

 

Thank for sharing your knowledge with us

 

Jack

 

 

Emily, The Very Yellow 21

[Roger King]

Head gasket failure - you're right on both counts, because either can cause it, but with overheating it is often the failure of the gasket first that causes the overheating.

 

Other possible causes include detonation, too high a compression ratio for the quality of the gasket, liner movement (especially K-series), etc. No doubt someone will suggest some other causes.

 

Multi point injection is where each cylinder has it's own injector, whereas single point has just one injector for the whole engine.

 

With single point, the induction system has to branch out from the injector to each cylinder; this gives rise to several problems - a tortuous inlet route which limits the amount of air that the engine can breathe, poor mixture distribution between cylinders, tendency for fuel to condense onto the inlet system walls as it negotiates corners, etc. All of these are bad for power, economy and emissions. single point can be regarded as being akin to a single carburettor.

 

A multipoint system allows a much more direct inlet pasage because there is no requirement for all the air to pass one point. It also guarantees that each cylinder will receive exactly the same amount of fuel and there is less condensation of fuel onto the inlet system walls because there are far fewer corners to negotiate. This is akin to a multi carburettor set up where each cylinder has it's own carburettor barrel.

[Big Brother]

Watchdog said its because the Rover supplied items are defective by design and a well known weak point for the K series engine.

 

 

Steve

 

Se7en-Up!

[simonbell]

My father inlaws K series gasket has just blown at 37000 miles.....absolutely scandalous in my book!

 

I could maybe understand if he was thrashing the nuts off it but he hasn`t been, it`s been 37000 gentle, easy going miles

 

FOR SALE Birkin S3 2.0 Zetec 170bhp FOR SALE

I`ve seen the future.....and it`s powered by duratec

[old captain slow]

Mine's just come up to 36000 so any time now?

 

C7 CDW

[Peter Carmichael]

Watchdog said its because the Rover supplied items are defective by design

 

While something is evidently amiss, the above statement is not accurate - barring a problem with

the silicone tracks (which probably only showed up when other problems are on their way), the head gasket itself does not fail - this might seem like weasel words, but it becomes important if you are trying to fix the problem as an engineer rather than trying to get a story as a journo who is on the track of scandalous exploitative activities of BIG BUSINESS. I think this mockery of a consumer programme ably demonstrates all that is rotten in the BBC and its tax-funded soft-left bias.

[Johnty Lyons]

I have my own pet theory about this and it's backed up by a rover dealer, but its still way out on a limb.

Ks are very fussy about inhibited cooling and are prone to blockages and sludging if not maintained correctly. The water rail on a K is mild steel and some of the welding/brazing is pretty crap, there are also a myriad of hoses on a std K installation. So within 12000 miles Ks atart to loose a little water, Now all forecourts have large green watering cans filled with tap water, and your good Mr Average consciously tops up his cooling system every time he opens his hood on the fourcourt so Inhibiter gets diluted , damage gets worse, more coolant lost, more tap water added, [ getting the picture?] Car starts to run more and more with coolant not fully topped up, localised boling occurs in that terrible cyl head design and here it come steaming down the tracks Head Gasket failure

 

Now onthe other hand take your fussy Caterham owner running 100% Rover 4 year or Comma equivlant, plus possibly some water wetter as well, in a highly tuned 200 BHP K he has no cooling problems and no head gasket failures at all, after 5yrs hard use.

 

Well I said it was a pet theory but the dealers I spoke to said that on 100% of head gasket failures they examined there was litle or no trace of the correct coolant and lots of signs of water loss.

 

So maybe it's not PTPs fauly maybe its the servicing or lack of it by the dealers

I actually sat in a Rover dealers showroom over-looking the forecourt and in the space of 2 hrs saw 7 Rover owners pop their bonnets and top up their washers and their expansion tanks with tap water. When I pointed it out to the service manager he thought about it for a minute or two and then admitted "You have a point"

 

jj

N.I. L7C AO.

Membership No.3927.

 

Edited by - Johnty Lyons on 9 Nov 2003 13:13:10

[simonbell]

jj

 

Quite rightly if someone tops there coolant with bog standard tap water then they should expect head gasket problems, cooling problems etc.

Maybe the manufacturer should put a big warning on the coolant cap

 

FOR SALE Birkin S3 2.0 Zetec 170bhp FOR SALE

I`ve seen the future.....and it`s powered by duratec

[thinfourth]

Okay i follow the tap water theroy now as a seven owner or potential owner in my case what can we do.

 

Now if we get caught short out on the road then we can top up with raw water. but we will nevr know how much we put in apart from a guess.

 

So carrying premixed coolant wuld be an answer all be it a heavy one.

 

So how about a 2 litre bottle with enough concentrate to make up to 2 litres ?

 

 

[Johnty Lyons]

If you carry the Rover 4 yr or equivqlent it goes in neat so no nead to dilute But more importantly why top up it's asealed system if you have to top up youve got a leak and are already heading down the blown head gasket road ☹️

 

jj

N.I. L7C AO.

Membership No.3927.

[Graham Perry]

Does anyone know Why the Rover K needs a special coolant ? There are a great many cars out their now (must be well over 50%) with either Ali heads or blocks or both, but they don't all recommend neat Coolant / inhibiter. Most just say use either the Red or the Green antifreeze, which you mix with water. The Caterham cooling system is a lot simpler than the Rovers ones though so there may be something in that.

 

Agree though that once you need to top it up once you are already at the top of a slippery slope. Some cars can cope with sealing compounds. My brothers 205 showed all the signs of H/gasket failure four years ago ie lots of water usage and no leaks. Not wishing to do a head gasket on a car with little value we added some sealant to the coolant. Its done 30k since then and no problems and seems to be fixed. By the sound of things though this would probably make things worse on a Rover

 

Edited by - Graham Perry on 10 Nov 2003 07:40:47

[Swiss_Tony]

Peter C

 

Can you explain a little more please?

 

James

Su77on Se7ens

 

[scooby dooby doo]

Very few engines are all alloy I thought 🤔

 

The other issue us that the liner on the K is only clamped by the head gasket - I believe this is unusualt as well - is it 🤔

 

so its more prone to moving which can lead to a failure around the fire ring.

 

speculation to try and tempt PC along 😬>

 

 

HOOPY

R706KGU Hoopylight R

[DanB]

Quite a few engines are all alloy Hoops. All Peugeot XU engines (as fitted to 205 GTis, 405s, 309s etc., including the diesel models) are all alloy. A lot of Honda engines are all alloy as well. It's not unusual, to quote Tom Jones...