BHG repairing - How do the internals look?

[MWP]

Hi all,

So i got a BHG on my Starlet GT (4E-FTE) last week.
It was only a small BHG (pushing a little air/water into overflow bottle eventually draining the rad), clean oil.

I got the head off this arvo, no obvious defects in the HG seal.
This is how it looks....

#1


#2


#3


#4


#5

How does that look to you guys?
Typical?

Car has 160,000km on it, not sure if the engine has been rebuilt during that time.
Its gets 15W-40 every 5,000kms and ULP98 fuel since ive had it (~1yr).

[neal]

They look better than my 7MGTE

[fixeruperer]

looks pretty tired, has lots of carbon build up and those bores are pretty glazed.
put some petrol in the ports and looks to see if you have any leaking valves.
looks like its burning lean aswell.

[hosking1991]

I suggest to get a clean' pressure test and surface grind

Also check water jackets are still within the gasket (aren't corroded)

Luke

[MWP]

The head will be getting dipped, hardness tested, crack tested and a surface grind.
Possibly new stem seals too.

[hosking1991]

I surface ground about 6. 4 cylinder alloy heads today which were warped a good + 10 thou

so id say its a good chance its warped

let us know how it goes

oh and get a vacuum test also just to make sure those valves are seating correctly

luke

[web]

Bores look fine to me, they have the slight dullness of a good hone pattern, I don't see a "polished" glaze finish. But that can be hard to see even in person, let alone from pics.

Does look a bit leanish, but you could've told that from the plugs. Not worried about a bit of carbon after 160k though - I've seen much worse. This looks like it's flaking off too, being broken down. Buildup from the past.

The sludge in the head looks like it's being broken down too. I don't think all previous owners did religious oil changes. Although I wouldn't use 15W40 mineral oil (?) in a turbo engine, the 5k intervals are probably slowly cleaning out the engine. Now that you have the head off, definitely throw it in a parts washer and have it checked for warpage.

[web]

Oh, and use OE valve stem seals if you replace them. With some aftermarket crap, it's better to leave good working old originals in

[Gavatron]

2nd to bottom pic the bores look anything but "slightly dull". Looks pretty glazed to me. Looks like the previous japs didn't look after it. Those heads stay very clean if they get regular oil changes.

[MWP]

The bores had a slight oil film on them in those photos.
I just wiped it off and took a closer look.
Can clearly see the honing pattern, and i can feel it when running my finger nail over it.

The oil ive been running is Penrite HPR15.

BTW, is it normal for a headgasket to block off a lot of the oil/coolant galleries?
Im guessing it is as its a genuine toyota item.
Why do they do it though?

[web]

Yeah, the reflections in that pic sure are deceptive.

What helps when trying to spot glazed bores in pictures, is looking for differences between areas that normally glaze first, and those that seldom do. On these I saw no difference, therefore I saw no reason to call these bores glazed.

Glazing usually starts as an oval spot centered halfway down the stroke in the thrust direction, and grows from there.

Of course that's easy to say, just under a posting confirming there still is a hone pattern... lol

Oh, and HPR15 is semi synth, that's at least semi good Most 15W40's here are mineral, so I made an incorrect assumption there.

[allencr]

How does that look to you guys?
Typical?
every 5,000kms

It looks very good for anything over 60K Mi/100K Km to me.
If all those little hone marks that you can feel are completely filled with baked oil, then they won't be able to hold enough real oil to lube things.
Thanks for the nice pics. In pic img84.imageshack.us/img84/7130/img3448gu2, the HG on cyls. 3&4 or 5&6, sorry I don't know which, looks like it has a very clean & polished looking fire ring.
Did you clean up the gasket on the last cylinder? If not, it looks like that HG doesn't have any flow at all into the head around that cyl., and that the head has been moving around a lot, expansion & contraction and that has been rubbing them together, cleaning them up.
Did it over heat a lot?
ALSO, are we missing a picture, I don't see a [B]BHG,[?B] so it's a loose weeping HG somewhere: never retorqued, or a mis-diagnosis??

Also, "Possibly new stem seals too."

[MWP]

Im 90% sure it was a BHG.
It was pushing air/coolant out slowly into the rad overflow tank constantly, and thats with the old and a brand new rad cap.

Its only a 4cyl car
The first two block photos are with the HG still in place, the 3rd is with it removed.
I couldnt see any obvious signs of a BHG either... but possibly a little leak at one place.
The head bolts didnt feel too tight when i undid them.

It never overheated until it did very recently (went off the temp gauge) due to it blowing all the coolant out of the rad on a long drive.

Thanks for the continuing analysis guys, +rep for all.