cracked head symptoms

B

bongskag

Member +
took my car for MOT, it was running fine for months, and he managed to overheat it somehow.. he topped it up with tap water after it over heated. I dont think he gave it chance to cool down first either.

now it smokes on boost and I have oil over where the manifold surface meets the head. no / oil in water or gunk. It has been built and running fine for 8000miles (forged) someone said it may be the valve seals installed incorrectly ?.

now it drinks about 200ml oil per 50 miles , which is quite a bit. Im gonna have to pull it apart anyway , any idea how to check its a cracked head and not just seals / or head gasket..

thanks in advance !
rob.
 
davehart

davehart

Member +
My guess is that he's been thrashing the living shit out of while he had it in for an MOT.

Or a possible coolant leak somewhere?
 
Jay

Jay

Admin
Sounds like he's cooked the engine which would point to a headgasket.

Headgaskets are designed to fail before engine damage occurs but it's still possible to warp the surface of the head and in extreme cases warp the block too.

A compression test tells you if the cylinders are holding pressure. If you find bad results a cylinder leakdown test will help diagnose in which area the fault lies.

My guess is you will take the head off and find the gasket blown. A good engineering place can test the head for you and skim it if required.

Hope that helps,

Jay
 
B

bongskag

Member +
thanks for all the reply's

the clue must be in the leaky oil around the exhaust manifold. its inbetween the runners. and under the manifold , looks like its leaking above where the head meets block.
I will get a compression test done , then a leakdown test. just hope its not a cracked head , but still the same ball ache as the head must come off anyway if its the head gasket :/

thanks again,
 
B

bongskag

Member +
quick thought .. im using a trd 0.6mm gasket , never had it retorqued since building , used arp bolts and grease. any chance it just needs a retorque ? im wishing for an easy solution ! lol
 
G

GP82

Member +
You would be lucky if that worked reading as the motor overheated, but there is no harm in trying. Crack each bolt loose before you torque them up again following the tightening sequence.
 
Jay

Jay

Admin
Was in the same sort of situation myself last week (headgasket concerns) and a retorque didn't help but it is still worth a shot.
 
B

bongskag

Member +
Its cams out even If I want to retorque it .. sounds like a longshot and I might still have to replace the gasket or even worse a cracked head .
Ive got a spare head, just needs rebuilding as its old and used . I guess its worth going all the way and replacing both the head and head gasket to be safe.
I can have a good look at the old head when its off,
is it still worth getting a compression test ? what else could it suggest . ringlands possibly ?
 
G

GP82

Member +
For sure do a compression test before you pull the motor apart!

If you then decide to take it apart, inspect it and the problem will introduce itself; Hello bongskag, i'm a headgasket and i've blown myself, please fix me :)

Did you try retorque the head then?

Did you check the car to see why it overheated, did the rad fan kick in? As mentioned, did the water run low or was there a leak? What a chuffin' ballache.
 
B

bongskag

Member +
Im sure Ill find out when I take the head off .. I may aswell build up a donor head and swap it out, it will cut down on the amount of time the cars in pieces ;)
its like its leaking between the exhaust ports , I'd have a go at a retorque if it was just seeping slightly from where the head meets the block.
if anything the gasket is doing fine, no water mixing with oil or overheating.. im guessing the head broke instead of the gasket ? or both, still a mystery

Ive found a decent thread on the subject of head removal .. just having a read now , doesnt sound too bad If I have a head all skimmed and built ready to drop in , http://www.toyotagtturbo.com/forums/showthread.php?14222-Removing-the-head&highlight=headgasket
 
B

bongskag

Member +
the donor head idea is now out of the window .. check this out, wear on the cam or what ! so I have 2 useless heads .

AMBA0014.jpg



looking for a 4e/fte head if anyone has one .. thanks.
 
B

bongskag

Member +
I'd been driving for a long time since it overheated. it wasnt loosing oil bad at first. I just put it down to the old Rad cap, as the reason for the random overheat as the fan was working fine , and couldnt see any coolant leaks. new water pump and thermostat .. upgraded to a 1.3 bar rad cap.! it wasnt until I saw the oil under the manifold that I realised I had a problem !! I just assumed it was the turbo smoking and changed that too,

started taking it apart a few days ago, still may need a new head, or just gasket. but I checked the ARP Headbolts and went round at 20ftlbs then 30 , then 40ftlbs and 2 bolts stared to turn , carried on up to 60ftlbs in sequence ... where the oil was leaking from the gasket thats the same area where the 2 bolts were slightly loose at the front, a few others turned too at about 50ftlbs.
. I read a few things about having to retorque ARP bolts , and some people do and some don't but I guess this is because of the random overheat. and now the head , and or gasket is gone .. just waiting on parts now, I'll post a pic of the old gasket when I go to change it,
 
dac69er

dac69er

Super Moderator
In an ideal world you should retorque everything once it has been through a few heat cycles. This ensures everything is at an even torque once settled.
In practice it's not exactly easy to do though.

I'm surprised you had 2 bolts turn on you at 40ftlbs. Maybe you missed the final torque stage on those bolts or didn't leave it long enough between stages to settle?
 
B

bongskag

Member +
yeh 40ftlbs seems a bit low, I was supprised too, I might see what its like if it still smokes a bit and drinks oil I will have to pull the head , It wasnt mixing oil with water , just drinking some oil which seems strange. and seeping out of the manifold area and dripping down the block. Thats why I thought it might be a cracked head for some reason,
 
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