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Bf5 Proformace problems and head gaskets


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#1 Outsider-josh

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Posted 20 May 2019 - 8:14 AM

Hi all im Josh new to this forum and Subaru's

Have problems with my 1989 turbo legacy wagon has a vf10 air to air top mount aftermarket downpipe (3inch at a guess),

Problems coolant is being pressurized after highway speed driving also bubbles from coolant tank with radiator cap off gets worse with a rev/very small at idle ,now I'm assuming its head gaskets due to it been sitting for sometime with brown water in coolant system

Also have done compression test showed 125psi to 140psi and a leak down showed air in crankcase at worst 80% leak down .I was using a cheap leak down tester from T.M

Thing still starts and idles fine not smoke from exhaust from what I have seen from the short test drives I have done has never overheated on me or run low on water the headgasket may have happened on my test drives bit never overheated
Also the thing is real slow

My question is rebuild of replace?

I'm leaning towards rebuild

#2 mjlqtown

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Posted 21 May 2019 - 3:47 AM

My BG GTB had a head gasket leak. It used to just push coolant into the overflow but not overheat. New head gaskets were defiantly the fix for me.

As for the compression test, it could be just a coolant passage leak and not a oil passage. I'm not sure how much compression you would lose, or depending on how bad it is.

 

It's probably worth doing a heater core flush as well. Rusty water often kills them. 

Also welcome along! and hopefully someone who knows better than me can offer some insight. 


Posted ImageYea right by Mitchell Lindsay, on Flickr

#3 Outsider-josh

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Posted 21 May 2019 - 5:21 AM

Definitely a head gasket leak in to coolant. Bit the leak down showed air coming from oil cap/dipstick so that would mean rings as well. Have the started collecting parts have genuine MLS headgasket and rings and bearings on the way

#4 DCVR

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      1989 BF Legacy

Posted 21 May 2019 - 10:56 PM

Hi all im Josh new to this forum and Subaru's

Have problems with my 1989 turbo legacy wagon has a vf10 air to air top mount aftermarket downpipe (3inch at a guess),

Problems coolant is being pressurized after highway speed driving also bubbles from coolant tank with radiator cap off gets worse with a rev/very small at idle ,now I'm assuming its head gaskets due to it been sitting for sometime with brown water in coolant system

Also have done compression test showed 125psi to 140psi and a leak down showed air in crankcase at worst 80% leak down .I was using a cheap leak down tester from T.M

Thing still starts and idles fine not smoke from exhaust from what I have seen from the short test drives I have done has never overheated on me or run low on water the headgasket may have happened on my test drives bit never overheated
Also the thing is real slow

My question is rebuild of replace?

I'm leaning towards rebuild

 

welcome bro 89 RS owner here if you have the time and coin go ahead and do the work


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#5 Outsider-josh

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Posted 23 May 2019 - 7:47 AM

I Have the time not so much coin. On the hunt for good reasonable price parts . Plan is to rebuild and put a td05,yellow injectors,bigger top mount intercooler, chip the ecu for mods or find a cheap link (or if theres a stock ecu that will work with that set up) . Is There anything else I should be doing to support the tdo5 turbo . Have got a new 320lph fuelpump in it already

#6 DCVR

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Posted 23 May 2019 - 7:53 AM

I Have the time not so much coin. On the hunt for good reasonable price parts . Plan is to rebuild and put a td05,yellow injectors,bigger top mount intercooler, chip the ecu for mods or find a cheap link (or if theres a stock ecu that will work with that set up) . Is There anything else I should be doing to support the tdo5 turbo . Have got a new 320lph fuelpump in it already

 

I have some of those things ur looking for do u have messenger? add me as Josef Legacy


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#7 Outsider-josh

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Posted 23 May 2019 - 8:18 AM

Thanks will do, I'll get the rebuild done first b4 the upgrades. Looking for some head studs preferable ARP .new engine gaskets/seals all except headgaskets . Also what kinda sealant is best to seal the blocks/cases ? from what I've find online it that three bond is best to use

#8 DCVR

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Posted 25 May 2019 - 8:19 AM

Thanks will do, I'll get the rebuild done first b4 the upgrades. Looking for some head studs preferable ARP .new engine gaskets/seals all except headgaskets . Also what kinda sealant is best to seal the blocks/cases ? from what I've find online it that three bond is best to use

 

3bond yes


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#9 Dundaberg

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Posted 27 May 2019 - 4:12 AM

Welcome bro. Threebond is the bizzo there, and less is best! I would strongly suggest saving for a new Link plugin ecu. $1400, plug it in, do some quick calibration stuff and you can literally start driving again. You wont have 200kw off the bat but it is reliably drivable. I won one a few years ago now, but daily drove it on the base map for well over a month and then drove it 400kms across Arthurs Pass to Christchurch for a tune.


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