Astina - Mazda Etude - Cylinder Head Gasket Replacement

[Globe76]

Hi Forum Members

I am a rookie doing a head gasket replacement on my Mazda Etude 160e 1999 Model 16valve DOHC, BP Engine I think??

The Gasket Failed due to car overheating, as Radiator was faulty. I have replaced the radiator and the thermostat and sent the cylinder head in to shop for pressure test and skimming. All valves and Valve Guide have been replaced.

I torqued up the cylinder head, using the Protege Manual,(Which I assumed was the other name for the Etude) The torque values were shown as 17-22Nm then turning the head bolts a 85-95 degree on two times. I did to the torque settings however I only turned a further 45 degrees as I was scared of shearing head bolts.

I put engine together and ran engine up to normal operating temp. I noticed a trace of black oily smoke coming from the one area where the block and head join(Where the Gasket is) I assumed I did not torque up correctly.

I have just found the correct Manual on this site for the Mazda BP-DOHC and see that it is actually this in fact the correct manual. In this manual they show that the cylinder head bolts need to be torqued up to 76-81 Nm

I would like to know if the head gasket which is new will be damaged from running the engine with it not torqued correctly for a few minutes(Normal Op Temp Reached) Could I loosen the head bolts(Which are Non-Stretch) and then retorque to the 76-81Nm (as per the correct manual on this site) and use the same new gasket or do I have to replace the gasket and retorque to the correct torque values???

Please help, I am a rookie, this is my first major Petrol Engine D.I.Y Repair and have invested alot of time and cash in trying to sort this out myself.

This Manual I just found does not seem to have torque values for the Inlet and Exhaust Manifold nuts that get tightened on studs?

Any ideas please?

I hope that someone can advise me please.

Thanks

Globe76

[project.r.racing]

First thing you need to do is find out what engine you actually have. "BP engine I think?" ain't that good place to start.

I though 160e had 1.6L engines and 180e had 1.8L engines?

I didn't even know that BP engines were still being used in 99 in FWD format.

What is the engine number? B6xxxxxx/BPxxxxxx/ZMxxxxxx/FPxxxxxx?

[Globe76]

On Metal plate inside the car it says

Model - BMGBP4102, It is a 1,6L

Rest of Info from ID Plate is as Follows

Chassis - BR274682
Trim - XJM
T - 1128Kg
V - 1528Kg
P/D - 81Kw
GA/BA FRT - 845Kg
GA/BA RR - 800Kg
GCM/BKM - 2510 Kg
GVM/BVM - 1570
It also has ZZM stamped on there and a long number which I assume is the serial number.

Hope this can help someone give me correct info.

I am hoping that I can use the same gasket?

Thanks for reply

Globe76

[project.r.racing]

Originally Posted by Globe76

Model - BMGBP4102, It is a 1,6L

That is the chassis/vin number.

The engine number is on the engine, some on the front near the gearbox bolts.

Or take a pick of the engine and post it up???

[Globe76]

Thanks for quick reply, Its early morning here and I need to try sort this out today.

Here is a link to my photoshelter Gallery. The Pics are in Car Stuff Folder.

These pic were taken while I was dismantling the car.

Thanks again.

Link

http://www.photoshelter.com/gallery/...00sPUFogup1PA/

[Globe76]

The car is at my uncles house up the road, so cannot check the Number near gearbox just yet.

I think it said somewhere in the owners manual it was BP?

I will check laters, I am hoping to get this back together during the course of the day.

Also need to replace the alternator as the Bat light was on when the engine was running. So I assume this meant the alternator was not charging??

[chewyryce]

ok see the 5th picture? well thats the block and the engine number on a DOHC is normally printed on the passenger side that is facing the radiator. it looks like a BP motor but just check it and make sure that it is.

Chewy

[Globe76]

Thanks folks but, what about not torquing it up correctly and running the first time up to operating temps? When I undo and retorque to the correct Nm can I use the same gasket(It is brand new...Ran car for like 10minutes)

Or do I need to replace the Gasket??

[70NYD]

thats a B5DOHC or a B6DHC going from the IM allone

[Globe76]

Thank but any ideas on Torque for Head Bolts?

[chewyryce]

Originally Posted by Globe76

Thank but any ideas on Torque for Head Bolts?

bolts should be reusable. as for gasket im not sure. ive never removed and reused a new head gasket before

[70NYD]

you didnt stress them too much. theoretically, head bolts should be used only once or twice. but seeing how 99% of the time bolts are desgined with a minimum fs of 2, you will be fine (especialy since u didnt torque it down much at all)

[Globe76]

Well I am tempted to try use again as I just replaced, Only installed and ran for 10 minutes maximum at Idle RPM 900 at obviouslly incorrect Torque Values. So going to retorque with correct Values once I can establish this.

Thanks folks.

[Globe76]

Reuse the Head Bolts and Gasket that is

[Globe76]

Okay I have just seen it is a B6 DOHC Engine 1,6L

Anyone know the torque spec or where I can download the manual from please???

[BGSP]

According to Autospeed.com.au it's 137 NM of tourque if you want more info here's the site http://autospeed.com.au/cms/title_Th...1/article.html

[chewyryce]

Originally Posted by BGSP

According to Autospeed.com.au it's 137 NM of tourque if you want more info here's the site http://autospeed.com.au/cms/title_Th...1/article.html

LOL. thats not the kind of torque that he was after. he's after the torque adjustments for the cylinder head bolts.

[chewyryce]

well your engine would fall in with a 323 BA. there are 2 types of head gaskets though. earlier B6 engines from 1994-1996 use Graphite head gasket and later model B6 1996-1998 use Laminated Steel. figure out which one yours is and find the correct torque settings for that.

[BGSP]

Oh he means torque adjustment :P I feel dumb

[Globe76]

OKay we getting closer thanks for the input everyone

The Gasket is Steel but I do not have spec sheets to check the torque to use.

I went to workshop up the road and they say 81Nm, however now I am sceptical as it depends on the original Gasket used.

No one have any Specs for all the torque essentials for doing top end overhaul??

Laters