Lane

It's a '92 SE5 that I'm bringing back to life. I've replaced just about everything you can maintenance-wise - but still felt a miss and lack of power...

Did a compression check today and barely 50psi in #6.

The truck has been in the family for a while and has always made a ticking type sound right there and I guess we found out why.

Before my sister in law got the truck, the head-gasket recall was done on it. Then the motor went south on her 4 months later. It was replaced I believe - but has always made the suspicious sound, which we chalked up to valve-train noise. When I changed the plugs I noticed that plug looked like it hadn't burned right. I rechecked the new plug and it seemed fine - but, now it's bad too...

The truck has recently sat for a long time without a gas cap on it . We replaced the fuel filter - and cap - and ran some injector cleaner through it. I also cleaned the TB out, which was beyond nasty.

I'm going to run some engine clean-out(44K) in it to see if it can be cleaned up. I'm hoping it's just carbon build-up keeping the valves from seating and not a bent valve or bad seat.. Then do another comp. test.

Any other ideas?

Could it be a bad head-gasket? Water and oil look fine and it doesn't leak a drop of anything anytime.

TIA

Firefyter-Emt

First, did you add oil to the #6 and re-do the compression test?? If not go do that, when you then find the same reading you will now know the fact that the exhaust valve on #6 is burnt. Once you are at that point, call Toyota,order a "Head-set" (That is all the gaskets needed to install these ) The swap is pretty easy, you will want to replace the water pump, timing belt, and PCV valve while you are at it..

I have done it a few times, if you have any questions feel free to drop me a line..

PS.. This is caused by the exhaugst manifoild design that takes all the hot gases from the left side of the motor and shoots it towards #6 and then takes all the hot gases from the right head up and over the tranny and dumps it right onto #6 and then they work their merri way out the bottom of said left manifoild to your tailpipe.. Can we say #6 is way overheated by the way it is designed??

Let me know when I am right..

Firefyter-Emt

Hmmm I just re-read your post, and if after the oil test, you still have 50psi.. It "may" be a bad valve adjustment.. But normaly a valve that is too tight will make less noise.. But you need to pull it down to at least the valve covers to check the clearance, this can be done with cheap feeler gauges.. I have yet to know the real reason why, but my truck had to be re-adjusted after about 3k twice after having the heads re-built.. and I am at 2700k on this adjustement and all seems good so far.. You didn't really say if they re-worked the heads.. Also, keep in mind.. the 3.0 is a noisy tickey motor.. Just the way it is, it does not have hydralic (sp?) lifters.. they are a solid, non-pushrod design..

Lane

Thanks for the replies! I have noticed smoke at idle - whitish for the most part.

Dumb question - but how much oil should I had for the comp test - and how do I add it?

Thanks again!

CTB

A white, sweet-smelling smoke coming out of your exhaust would mean you are burning coolant.

Firefyter-Emt

Yep.. white smoke at idle would go back to indicate a bad head gasket.. if you add oil, I normaly give it a tablespoon of 90wt via the 90wt oil jug.. (it just fits eaisy) or you can doo a table spoon thru a funnel.. It does nottake a lot, just enough to seal bad rings.. I recently did my Jeep.. I have 70psi on #4 I added the oil and it jumped to 195psi.. My rings were gone (175,000 though..)

Lane

I wouldn't call it sweet... I haven't payed much attention to it because I know I've got exhaust issues and am waiting on a new high-flow cat and Dynomax system. The stock system is rusted out..

Lane

I'm still not sure what was done to the motor - or if it was completely replaced. I have a feeling something went wrong in the head-gasket recall work that blew the motor 4 months later. This was 5 years ago though and a private shop did the rebuild - so I'm still trying to dig up info and paper-work on it.

Who knows what was or wasn't done to the thing...

Toyo22R-E

Cylinder #6 is where the head gaskets usually let go. If you've got white smoke and a dead miss, that's where I'd look. Usually however, the coolant level will go down. In the mid-late '90s there was a campaign (V06) and I literally replaced dozens and dozens of sets of head gaskets on these things. That was the weak link, other than that not a lot of trouble with these engines... If it's been apart, I guess anything is possible though.

Firefyter-Emt

Well the HG and the valves around #6 are also a weak link.. It mostly all goes back to the way the exhaugst is designed.. The HG goes in that area due to the over heating of the head / block due to ALL the exhaust gas being dumped onto #6 exhaust port..

I still say do the compression test and see what that gives you, if it comes back low you either have a bad HG or a bad head.. either way, it has to come off.. You would want to send the heads out to be looked at anyway.. I say buy the heads I mentioned above, then sell your cores on e-bay..

Lane

The coolant and oil levels are constant. The coolant especially seems perfect - and it doesn't burn oil or blow blue smoke. I'm pretty sure it's ran on 5 cylinders for a long time - so it's probably the head.

Should I go ahead and pull the other one and check it too?

Firefyter - what's the benefit of those heads over reworking the ones on it?

Thanks again guys!

its2slo

if you did the headwork on your ls1 then i would definately work on the ones you have.

i noticed you had white smoke but said the coolant was fine, it took about 100 miles of driving (atleast) for mine to noticeably lose coolant and for the water to show up in the oil after mine let go...however the instant the hg let go it started puffing white smoke, and then it would go away, and then come back, and go away, and come back worse, and go away. the white smoke was definately intermitent. this was on a 3.4 btw.

Lane

Mmmm, I guess we'll just have to open it up and go from there.. We're going to run some BG 44K in the hope that it's just some carbon build-up, but I'm not banking on it helping...

BTW - I haven't touched the heads on my LS1 - or anything that motor oil touches for that matter. All stock internals and no juice.

its2slo

thats insane, lane. he he. when are you going to disclose the details on it? you dont even have a cam? omg....thats just too fast i thought my stroked lt1 was fast, but of coarse i also suffer from obesity (96 impala ss) yes, i know the ls1 is faster!

okay sorry to derail.

Lane

lol.

It's #4 in the country right now - with stock internals. The #1 time is 11.27 @ 120! But he was nearly 200 lbs lighter and in -1,500 ft DA. I was in +500 DA.

I'm looking to break that record this fall. I've add a tubular K-member and have the tubular control arms as well, but not on the car. Plus, I've done some more computer tuning. Lightweight carpet, remove the bumper supports - negative DA, a sticky track - and the record should be mine.

The car currently has all the bolt-ons, home ported TB, Mac headers with true duals, ASP pulley - full suspension with Hals(12 ways) on all corners. Slicks and skinnies at the track. LS1 edit - And most important - a Yank PT4200 converter.

its2slo

wow. g/l at the track lane, it would be fun to watch you drag race.

let us know how your adopted runner comes out, g/l with that too.

Lane

Here's a couple of vids.

Way off subject now!

This on an 1/8th mile track. 7.33, probably a 11.5X 1/4. Wish I had the 11.4X runs on the web.

http://rampageroad.net/video/kdale_3...ane_launch.wmv

This at Ennis on SLP Day. I was having some electrical issues and that was my only run of the day. I wasn't paying attention to the tree either - so I didn't flash the converter right. Still ran a 11.70.

http://rampageroad.net/video/ennis2_...ne_1170run.wmv

Back to the 4-Runner. If I pull that head and replace the bad valves(assuming thats the problem) - what does a valve job normally run for these things? I might go ahead and do both while I'm at it...

its2slo

yup, its fun to watch alright. you have definately masterd the art of a launch!!! even with the video its unbelievable....

oldsub86

You might want to try a cylinder leak down tester before you tear it apart. They are supposed to be more reliable than compression testers in terms of determining the health of an engine. Basically, it screws into the spark plug hole and then you pressurize the cylinder with air and listen to see where the air is leaking out. With both valves closed it should hold air pressure. If you hear air at the tailpipe it is the exhaust valve etc.