Buying A Gen5 Gt4 With A Blowing Headgasket

[Cexy_Ratt]

Off eBay.... It has just passed a full mot so comes with MOT, is totally standard and is white. But this is a big but it has a blowing head gasket ,it doesnt over heat yet, but has the usuall Mayo under the oil filler cap and on the dipstick. In my experiance of doing cars with over heating problems this usually indicate the H/G is blown

So i am going to put a new one , someone said that by putting a thicker metal one eg a blitz metal headgasket or similar it will mess up the boost / compression ratio's is this true, or should i stick with a stock head gasket. Also anything else i should be looking for.....

The car must be in good nic as its just passed an mot.

Also bleed valves and dump valves are these any good for the engine, what make should i be looking for. Anyhting else you would tackle or look at whilst doing the Head gasket..

Any info most aprreciated.. thanks

[Sketchy]

Off Ebay.... It has just passed a full mot so comes with MOT, is totally standard and is white. But this is a big but it has a blowing head gasket ,it doesnt over heat yet, but has the usuall Mayo under the oil filler cap and on the dipstick. In my experiance of doing cars with over heating problems this usually indicate the H/G is blown

So i am going to put a new one , someone said that by putting a thicker metal one eg a blitz metal headgasket or similar it will mess up the boost / compression ratio's is this true, or should i stick with a stock head gasket. Also anything else i should be looking for.....

The car must be in good nic as its just passed an mot.

Also bleed valves and dump valves are these any good for the engine, what make should i be looking for. Anyhting else you would tackle or look at whilst doing the Head gasket..

Any info most aprreciated.. thanks

Defo sounds like a HGF, get a compression check done as well just to make sure all is well.

185's are daks speciallity but from memory the stock headgasket has a tendency to go and the solution is to swap for a metal HG, getting a thicker one will lower the compression ratio a bit but not a lot. It will do nothing to the boost.

Would have though you can get a stock sized metal one, but I'd wait for dak to confirm that.

Bleed valves are a pants way of controlling boost and if it's got one would be a good pointer to the previous owner running higher boost and hence HGF.

If you want to up the boost use either a proper relief valve or an electronic boost controller. Dump Valves tend to be a bit hit and miss on the 185 due to it being an AFM based engine effectively your dumping metered air so the engine ends up running very rich. Again I'd wait for Dak for advise on that one.

[Cexy_Ratt]

The car is totally standard at the momment, no mods at all , so i am guessing its just the usuall blown head gasket. will compresion check it when i get there aswell.

so dump valves and bleed valves are a no no

[Sketchy]

The car is totally standard at the momment, no mods at all , so i am guessing its just the usuall blown head gasket. will compresion check it when i get there aswell.

so dump valves and bleed valves are a no no

Well relief valves are a definiate no no, there are better and just as cheap ways of controlling boost.

As for dump valves it can be done as dak and a number of other 185 owners have them, it just seems to be a bit hit and miss as to weather the car likes it or not.

[daktari]

Someone mention my name???? :)

GT4 Headgaskets not really my bag. I was fortunate mine was done before i got my mits on it allegedly. . Its not a major issue if you catch it early enough. As mentioned you can replace it with a metal HG. Thicknesses vary from about 1mm up to 1.8mm i think. Prices vary greatly. I wouldn`t go for a name i`m unfamiliar with. You don`t want to be putting something vital in your engine that was stamped out in a shed by a latvian goat herder. HKS gaskets have a good reputation although they cost more. You`d also want to be looking at some uprated ARP cylinder head bolts. Total cost of this lot would be around 150-200 depending on where you get them from then you`ve got to add on things like various gaskets & seals, oil, coolant. etc. Budget for around 250-300 quid including a head skim. Then you`ve to add labour on top if you`re not going to do it yourself. A standard gasket set for the GT4 is about 130 quid from somewhere like Fensport. :)

Before you decide on a Metal headgasket you need to think about future performance mods if any. If you intend putting a big tubby on and running big power you `ll need to go for a thicker HG to keep compresion ratios real world and reliable. I think most folk if they are just going for moderate increases go for 1.2 or 1.4mm. Not 100% on that. If you ask around on the other forums GT4OC & Celica club you should get some more informed answers. ;)

Dump valves. Again as stated bit of trial & eror involved. But you really need to get a twin piston jobbie. This only allows a limited amount of metered air out instead of dumping the whole !Removed! lot. I`ve got a Blitz and it`s pretty well ok. If you can borrow one to try you`ll get an idea before you part with any money. Again it`s the better quality DVs that seem to perform better.

Relief valves are a big no-no. They`re pants. A decent granger valve will suffice but a decent EBC setup will be much better and more controllable.

Not a whole lot of help but hopefully it`ll point you in the right direction.

[Cexy_Ratt]

Well i have just prices up the bits fron fensport £417 !!!!! for the parts, based on a metal headgasket. The HQS HG is £165 +vat, head gasket kit is £95+vat and the ARP studs are £95 +vat, eek

[daktari]

Well i have just prices up the bits fron fensport £417 !!!!! for the parts, based on a metal headgasket. The HQS HG is £165 +vat, head gasket kit is £95+vat and the ARP studs are £95 +vat, eek

Like i said. prices vary enormously. Scan eBay look at yank sites. I got an O2 wideband sensor for half what i would`ve paid over here inc taxes. Really good exchange rates. No dis-respect to Fennies but they aint the cheapest by a long shot.

[dawesy]

buy a set of ARP head bolts and a std ST-205 headgasket, about £45(metal as std) have your head refaced and clean the face of the block completely, best bet is use a fine grade emery on a flat steel block and use lots of spray oil.

when done bolt back together and enjoy

[Cexy_Ratt]

The head gasket for the ST205 is that compatible with the ST185, no messing about just simply replace part?..I am gonna gor for the ARP head bolts, at the edn of the day if i get this motor and spend the money on the head gasket things, i will have a st185, in nice knick with a HQS headgasket and a 12 month mot for under 1400 quid which is good going i think.

My dads a mechanic, done a few H/G's with him inmy time , so shouldnt be a problems doing the work

Is there anything else i should be doing apart from the cam belt when i am doing the head, gonna do the cambelt aswell

[irish_kev]

..have your head refaced

had to laugh when i read that

[Cexy_Ratt]

Can get the headset and bolts for about 90 quid off eBay, non ARP bolts just normal stretch bolts. 418 quid v 90 ..lol.....

Could do find out if the ST205 one will fit, and if the all the other gaskets are the same.....as the ST205 that come witht he head set.

..have your head refaced

had to laugh when i read that

[Sketchy]

Don't know if it's exactly the same but their are some guys on the gt4oc that have put 205 heads on 185's so would have though it could be a goer