Engine knock - Toyota Nation Forum : Toyota Car and Truck Forums

ebolabar · 09-24-2007, 01:28 PM

Hey guys,
I dunno if anyone remembers but I posted about a month or two ago about my new 87 NA. In the post I mentioned that my engine was knocking (which really doesnt make sense cuz its only got 75k miles on it). I brought it down to florida with me and I admit that here and there I did kinda "push it to the limit" until one morning I started her up and found that the knock had degraded into a much "deeper", more noticeable knock that made the engine shake the entire car, especially at idle. there was a very noticeable smell that came along with the engine knock, and I'm almost positive that the smell is burning oil. This is weird because Ive always had oil on my spark plugs, but never the smell. I'm kinda embarrased to mention this, but when I checked my oil, it was quite low, so I changed it. Now if I start the car after a looong rest, like in the mornings, she's just fine except the smell is still there even when the "deep" knock isn't. But if I park and come back later (like within an hour) she's back to the super deep engine knock. The knock is the worst at low rpms, but still noticeable at high rpms. Me and a friend are gonna change the valve cover gaskets today, and maybe even the upper intakes too (some1 mentioned galley gaskets so i'll look into that as well).

If anyone has anyinsight into my problem, please share. If theres anything I should do while i'm in there, lemme know. thanks in advance.

***kamesama980*** · 09-24-2007, 06:48 PM

sounds like rodknock except for the whole 'different smell' and shaking. I hate to be the bringer of bad news but it sounds like you've contracted the ubiquitous 7m blown head gasket.

Jeeves · 09-25-2007, 10:11 AM

Sounds more to me like you've potentially got rodknock and a BHG. Talk about bad luck.

ebolabar · 09-25-2007, 01:01 PM

I checked the engine yesterday after I drove for a bit, and I saw that the engine was smoking (quite visibly) near the back of the engine, so I'm pretty sure its a BHG. ok, so I'll go into the head and fix the head gasket. No big deal right? Im sure I can do it myself. Are there any guides already posted on fixing a BHG? Only thing that worries me is the rod knock, cuz it might be out of my means. Unless anyone knows of a feasible way to fix it. Thanks guys for any input you might have.

Jeeves · 09-27-2007, 01:30 PM

Quote:

Originally Posted by ebolabar

I checked the engine yesterday after I drove for a bit, and I saw that the engine was smoking (quite visibly) near the back of the engine, so I'm pretty sure its a BHG. ok, so I'll go into the head and fix the head gasket. No big deal right? Im sure I can do it myself. Are there any guides already posted on fixing a BHG? Only thing that worries me is the rod knock, cuz it might be out of my means. Unless anyone knows of a feasible way to fix it. Thanks guys for any input you might have.

It's not quite So simple. You have to strip the engine down to this point:

[img]http://**********s.com/supra/currently.jpg[/img]

Then you have to clean both the block and head, ideally to a mirror finish, but you won't do that in your garage. Then you need to reinstall everything and follow the EXACT steps for torquing down the head.

ebolabar · 10-01-2007, 11:13 AM

mmm. any special tools required to get it to that point? I've got the basic sockets and ratchets and a vice grip. I know i need a torque wrench for the HG. Thanks for the pic btw.

shaeff · 10-01-2007, 05:39 PM

heh, i have that same duralast battery. :p

-shaeff

Jeeves · 10-03-2007, 12:26 AM

Quote:

Originally Posted by ebolabar

mmm. any special tools required to get it to that point? I've got the basic sockets and ratchets and a vice grip. I know i need a torque wrench for the HG. Thanks for the pic btw.

Just based on what you've said, I don't think you've got what it takes to pull that head and do this work.

Quote:

Originally Posted by shaeff

heh, i have that same duralast battery. :p

-shaeff

Two Mk3 owners can't be wrong!

Question, did you get a battery tie-down to fit it? It's shorter than the stock battery so the stock tie down doesn't even touch the battery. Realized this right before I tried to take it to the track. Won't pass track tech without one.

ebolabar · 10-03-2007, 12:47 PM

I understand why you might feel like that, but being on a college budget cuts my options in half. Of course I'm hoping that it's not a BHG, but if it is, I'm stuck fixing it myself. However, I really would'nt mind some help from people who know more than I do. But regardless, thanks for the input.

Jeeves · 10-03-2007, 03:43 PM

I'm just saying in it in all honesty. Here's the tools/parts I used asuming a stock hg failure:

Phillips screwdriver
Flathead screwdriver (and pry bar, in ONE tool!)
3/8" Drive Torque Wrench(es)
1/2" Drive Torque Wrench(es)
5mm hex head, 3/8" drive socket
8mm, 10mm, 12mm, 14mm, 17mm(?) 12pt, deep well sockets.
8mm, 10mm, 12mm, 14mm, 17mm 12pt, normal depth sockets.
3 - long 3/8" drive extensions
Needle Nose Pliers
Regular Pliers
Zip-Loc baggies (Needed the first time around, label constantly)
Razor Blade
Brillo Pads
New HG
ARP Head studs (or bolts)
- really you want to machine the head and block and you'll not be able to do that with the engine IN the car
etc.

It's nowhere near a simple task and doing it wrong will mean that it'll all be wasted time/effort as it'll fail immediately (or near) again.

ebolabar · 10-04-2007, 01:08 PM

oh boy. thanks for the list. im going to get it diagnosed this weekend for sure. got my fingers crossed