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Old 12-01-2009, 08:27 PM   #1
2Fast2Furious
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Default possible blown Head Gasket

POSITIVES:

* car doesn't have milky substance in oil cap
* temperature guage reads fine
* coolant is still at full level
* engine sounds good

NEGATIVES:

* there is a smell from under hood, I thought it was oil, I can't destingish if its the sweet coolant smell
* there is a substantial lose of power (very sluggish)
* idle's very roughly and engine easily dies off in idle
* some white smoke from exhaust
*coolant is grey but not sludge (though I heard this can be due to red and blue coolants being mixed, guess a coolant change is in order)

My local Toyota garage can't take her in until Monday next, I have already drove her alot and don't want to touch her again in fear of fecking the engine.

Could the lose of power just be spark plug problem?
Could the grey coolant simply be a Water Pump seal leak problem?

If I do need new Head Gasket should I just go for stock part? Are they aluminium?

Would it be worth going with:

ARP head studs and a 2mm thick piece from HKS and fitted with 1mm oversized valves, and stock cams fitted with AEM cam gears. (lol, not sure what this is all about but if its good I will pay)
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Old 12-02-2009, 01:51 AM   #2
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millimeters are pretty big measurements when dealing with engine internals... I've read posts where fractions of a millimeter are removed from the head and/or block... leaving room to make up for if you desire the correct compression. If you just throw a 2mm gasket on the block, I'm pretty sure you're going to change the volume within the head significantly and therefore change your compression ratio. I'm not sure if it's required, but usually trimming the head and/or block, or throwing in a stroker kit seems to address this a little better (from what I've read, open for any corrections that may benefit my knowledge and inform the OP otherwise)

I've always understood gaskets to be made of fairly cheap, almost cardboard like, material.. not aluminum or metal. The metal head gaskets are less likely to blow, but really not necessary unless you're putting out a lot of power.


Milky oil won't be in the oil cap, it'll be in the oil pan... easiest checked with a dipstick after the vehicle's been parked and sitting for some time (overnight) and the engine block is cold and fluids are uncirculated. I've also been told white smoke is usually a sign of coolant entering the cylinder and being burned off with the fuel.. which might be where the smell is coming from. However, given what you've mentioned, it really sounds more of an issue with timing than cooling or a BHG... properly timed engine should not idle rough and a poorly timed engine will be fairly sluggish.. you can also pull the plug wire for spark plug #6 and see if it has any moisture or oil. If I read and remember correctly, this is typically a sign of bad valve seals.

I know I'm not very knowledgable in cars yet, just applying logical analysis... so hopefully another poster can confirm or correct my statements and help point you in the right direction as well. Good luck, would like to know the end result once you find it.

Last edited by Krem; 12-02-2009 at 01:54 AM.
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Old 12-02-2009, 03:32 AM   #3
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lol same symptoms as my car. i thought it was a HG too but turned out i have 2 cracked pistons. if you check my thread the gasket isnt made THAT poorly... could be better. but i had a rough idle, loss of power, smoke out the mack of my car.... all HG symptoms. honestly you never know what it is sometimes unless you look under the hood yourself. or pay a shop a bunch of money.

http://www.toyota-supra.info/forums/...omorrow-6.html
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Old 12-02-2009, 03:54 PM   #4
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I was recommended mechanic near my work by a few people.

I brought it up to him, he reckons its the spark plugs so he will look at it on Friday when I'm at work - fingers crossed


A lad in work reckons its a fuel supply problem.
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Old 12-02-2009, 08:10 PM   #5
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Quote:
Originally Posted by 2Fast2Furious View Post
Would it be worth going with:

ARP head studs and a 2mm thick piece from HKS and fitted with 1mm oversized valves, and stock cams fitted with AEM cam gears. (lol, not sure what this is all about but if its good I will pay)
Is this a GTE or a GE?
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Old 12-02-2009, 11:19 PM   #6
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GTE however I probably won't need to change HG but please continue, I am listening


Misfiirng cylinders, however the variety of diagnosis leaves me wondering:

electrical, coil, spark plugs, idyling float, trottle positioning, it is earthing, let the fuel run to low and sucked bits at bottom of tank up, got bad petrol, head gasket, battery, air intake, carburator etc

We will know on Friday if its spark plugs?

Definitely know on Monday.
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Old 12-02-2009, 11:48 PM   #7
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without even hearing any of the other symptoms, misfiring cylinders would still point me to timing... but that will prob be addressed once you start lookin under the hood, since you are going to check plugs first...
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Old 12-03-2009, 01:21 AM   #8
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Have you checked for diagnostic codes?
http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

The grey coolant is NOT a good sign and it is something I would personally freak out about (there's little that freaks me out). If it is due to mixed coolant the system should be thoroughly flushed (chemical flush, not just water and a light detergent) and most types of coolant do NOT play nicely with each other (some even turn to gelatin on the walls of every surface inside to coolant system and just because it didn't all emulsify it doesn't mean none of it did).

I was asking if it was a GE or GTE due to your question about upgrades.

Quote:
Originally Posted by 2Fast2Furious
ARP head studs and a 2mm thick piece from HKS and fitted with 1mm oversized valves, and stock cams fitted with AEM cam gears. (lol, not sure what this is all about but if its good I will pay)
The head gasket would have to be changed when you install new head bolts or head studs (either would be fine and ARP is the manufacturer of choice for these fasteners).

A 2mm head gasket is only needed if you are planning on adding a much larger turbo OR if the block and head require significant milling. A thicker head gasket lowers cylinder compression which on a stock engine is unnessecary and will result in a decrease in power. The decrease in compression does allow for you to run a larger boost pressure though which can more than make up for the offset in base power. In a high horsepower build you would still (in an ideal situation, anyway) go with the thinnest head gasket allowable and use different pistons to reduce the compression ratio.

The stock valves flow plenty... especially if combined with a cam of a more aggressive profile. I would upgrade the cams before upgrading the valves. I would get the head rebuilt including a 5 ange valve job (a 3 angle valve job is more than enough, but if you want to go all out I'd go with the 5, it flows even better).

Adjustable cam gears don't always result in a power increase... they are used to tune the power curve to match your needs. They move some torque from one place in the curve to another. You could say they make more power in some cases as they may remove power from one area and add it to another, but it is all trade-off.


Quote:
Originally Posted by 2Fast2Furious
* there is a smell from under hood, I thought it was oil, I can't destingish if its the sweet coolant smell
If there is a smell, there is a leak... period.

Quote:
Originally Posted by 2Fast2Furious
* some white smoke from exhaust
Unless the smoke is black, it's oil or coolant (neither is generally a good sign).

Quote:
Originally Posted by 2Fast2Furious
If I do need new Head Gasket should I just go for stock part? Are they aluminium?
The stock head gasket is a composite graphite material with copper jackets.

There is nothing wrong with using a stock HG on a relatively stock system. The head gasket was never really the problem to begin with nor were the stock head bolts to be blamed; the torque level used on the head bolts was the problem... but then keep in mind that the stockers generally lasted ~20 years on the low torque level. Personally, I'd feel safe on a stock head gasket as long as VERY little material was removed from the head and block deck during the replacement at low boost levels. If you're going to be increasing the boost I'd go with a thicker gasket in which case a metal head gasket and the additional prep work are a requisite.
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Old 12-04-2009, 11:23 PM   #9
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no wonder there was such a lose in power she was running on 4 cyclinders. turned out it was a faulty coil. only cost €30 for a new one and to be fitted. he said there should be a great improvement in fuel consumption - heres hoping but she sounds great and drives great.

however the mechanic still recommended I go to Toyota garage for Diagnosic system test because the engine still cuts out ever now and again when near stopping in low gear which is unrelated to the lose of power which is now fixed. so I will leave her in on Monday.

turns out that ROCKET HEAD GASKET is leaking oil and that is the burning smell under the hood so Toyota garage can replace that also. I found a link below with same problem on Skyline http://www.skylinesaustralia.com/for...sk-t71313.html. It seems the leaking ROCKET HEAD GASKET AND FECKED UP IDLYING may be related or could just be a coincidence.

In the thread in link above it mentioned idlying problem having something to do with the throttle body bypass being dirty. What are your thoughts on this?

will keep you's posted.

Last edited by 2Fast2Furious; 12-04-2009 at 11:33 PM.
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Old 12-05-2009, 12:16 AM   #10
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Ok... I had no idea what you meant by rocket... that was a typo on their site and they meant rocker... not entirely accurate, we don't have rockers... it's more commonly called a cam or valve cover. Yeah, it's not uncommon for those to leak as the seals leak and the screws back out.

The bypass to which you refer is the idle speed controller... It is not uncommon for it to get clogged up with oil and dust over the years and as a result it may cause iddues with the idle.

As your valve cover are leaking I would first pull the spark plug wires and check if oil has leaked down in around the plugs; it's just as common as the leaking valves and can cause shorts.

To check for diagnostic error codes you simply need to install a jumper and count the flashes of the check engine light.... very easy and cheap. I'd start with that before paying Toyota techs to do it. :P
http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

If you're even subtly mechanically inclined I'd just replace the valve covers myself as well... the hardest part is disconnecting the throttle body (a whopping 4 bolts ). Wehn tightening the screws that hold the valve covers use some light strength thread locker and don't over tighten them.... they really only need the be a firm hand tight (just under 2 ft lbs or 2.71 Nm).
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