1/2' Torque Wrench OR Cordless impact wrench?

[joan33987]

Hello,
Just blown the head gasket on a 95 Peugeot 106 1.1 engine.
Because it smokes a bit and will overheat in less than a few miles.

I am going to "attempt" to change the head gasket on my own, but of course with the help of the Haynes Manual.

While I'm waiting for my Haynes Manual to come through the post from Ebay, I need to buy a Torque wrench, so that i could tighten bolts according to the values of the manual.

I'm thinking, if i am going to buy a Torque wrench, why not buy a Cordless impact wrench?
both could still precisely put out the amount of torque I want, wouldn't it? and the cordless impact wrench would be so much easier, would it?
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current toys: Skygo SG125-J 125cc stolen again 1992 Kawasaki GPZ500S (crashed damaged) 1996 Renault Clio 1.2 2005 CG125 project

[Phoenix]

I do believe an impact wrench is only designed to be used with large heavy bolts and threads and not something quite like engine head bolts. I'd get a torque wrench, i'd only use an impact wrench for things like wheel nuts, clutch hubs and so on.

[Casper]

You dont need one. Just tighten the bolts back in in order or you might warp the head. After about 100 miles pop the rocker cover off and give the bolts another 1/4 turn if needed.

[stonesie]

Torque wrench for re tightening, impact gun for rapid dis assembly

The 106 is a nice easy one really but the main thing to watch out for is that it is a 'wet liner' engine, the bores are all individual so once the head is off you must not turn the crank or there is a high risk of breaking the seal between the liner and block... That would let all the remaining coolant straight into the sump. and be a total mare to re-seat and seal.


The way to avoid this is simply to put a load of large sockets onto a pair of old head bolts with a big washer at the bottom, screw it in so the washers hold the liners down.

https://petrila.net/peugeot/Service/206/images/b/b1dp05zc.gif
That's the official tool for the job but holding them at 1 edge will do fine.

You must at least get the head skimmed while it is off and a pressure test is also a good idea

[Kickstart]

Hi

Impact wrench isn't designed for accuratly tightening up bolts. Just belting hell out of them.

Get the torque wrench.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[calyx]

Hi,
I have an electronic snap-on impact wrench with torque config. I use it to loosen/tighten sprocket's and rear tyre's bolt. Other than that, it has no use. And the torque setting is not precise either. It displays 110Nm but the torque wrench says 70Nm..

So +1 to "get the good old torque wrench"
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Boris - London

[G]

[Teflon-Mike]

Well a torque wrench is NOT a breaker bar with a wratchet head for doing / undoing 'tight' fastenings, but a precission 'setting instrument' for putting the last bit of pressure on the fastener to the precise setting......

You need a breaker bar to undo the old head-bolts AND to do them up, ALMOST to the desired torque.

AND a decent socket for the job. Most sockets under that much strain will simply crack.

Go to halfords / machine mart wherever, if you dont have decent sockets and get just ONE the right size for the job, from the 'Pro' range, along with your breaker bar and torque wrench.

As for the electric impact wrench, as said, they are NOT a precission setting tool, and in no WAY a substitute for a torque wrench.

They are a sort of combined impact drive, and windy spanner.

And £ for £, well power tools are always going to be more expensive or less durable. I mean, if you were buying a saw, which would you expect to last longer or take more strrain or abuse, a cheap electric jig-saw or an old fasioned hand-saw?

If you are investing in tools, invest in the tool designed for the job, and get the best you can for your money.

In this case, that = propper torque wrench, no question.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
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[Teflon-Mike]

Just thougt, 1.1 peugot engine.... if that is the old, I think its 1046 or something, single Over head cam 'slant four' they used to use, or a derivative, it has some err..... peculiarities.

One of them is that it has 'wet' liners.

Engine block is like an aluminium window box, full of water, and the liners sit in the water-jaket, with a bug rubber o-ring at the bottom, held in place ONLY by being pressed into the crank-case by the cylinder head on top.

They are notoriouse for blowing thier lids, and for burning oil, and when you lift the head, they are often banana'd beyond belief!

BUT takling the pressure off the liners, if you haven't drained teh water, the liners lift and teh water all pours into teh sump!

To 'do' a head gasket on one, is not as straght forward as many engines, you have to basically do a complete strip, becouse you need to lift the liners out and put new seals beneath them, which is awkward, if you try putting the liners back over the top of the pistions.

Usually ends up with the oil control rings (another nigly little design) getting snagged, and that scored the bores and leads to burning oil!

You cant really use a ring compressor working that way round you see.... so you have to remove the big ends from the crank... remove pistons and rods, re-fit liners with new seals, then put the pistons back in from above using a ring compressor....

THEN you have to get the cylinder head skimmed

And PROVIDED there is enough 'meat' on it to get it flat again...

Put it back on, VERY EFFOF carefully, following the torque pattern to the letter.... MORE doing it up in stages, like going round the pattern with the torque wrench starting at the bottom of the scale, then repeating putting on say 10ft-lb at a time until you reach the spec's setting, to make sure that the head goes down exactly flat, and you dont tilt the liners as you do it all up.

THEN you leave it all for a day or so.... and do it AHAIN, to make sure that the bolts have held the desired torque after the O-Rings and gaskets have settled!

Bludy 'orrible little engine to work on it is! GREAT when they are going, but GEEZ they are a pain in the arse for cooking!

Worth checking the rad & water-pump, thermostat and all hoses, to avoid it boiling its lid again, and DONT thrash the thing once fixed!

That's what REALLY kills them!

Trouble is, its a very lively little motor that likes to be thrashed! (In fact it wont go no-where unless you DO thrash it, but than that s the natuire of a small ecconomy car!)
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[DrDonnyBrago]

You can get away without an electric impact wrench indefinitely, a decent set of torque wrenches, sockets and breaker bars are worth their weight in gold .

[crackpotterpi...]

lesson to be learned there..............keep away from french crap! I speak from previous expercience
easy fix...............sell it.............drain the water and only run it for 2 minutes when showing the prospective purchaser.This way it will not leak or emit steam!!.............problem solved!!
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1990 jc20 nsr125-sold,2003 cg 125-sold currently no bike.........might get another 2 stroke me thinks much more fun

[stuartadair]

i've done one of these before and I'm sure it had wet liners, so the advice about being careful is well worth following.

If I remember right the Haynes manual doesnt list torque settings, rather angular settings, meaning you would need to buy another tool from Halfords.

For an aluminium head and block tighten down to 80 lb and you wont be far off.