compression test shows 150 psi over all four,rebuild time :-(

[mikey4410]

so after my dyno run with not to great results I have done a compression test which shows bang on 150 over all four so looks like somerhings worn out.

these engines are meant to have 175 stock and I know 150 is service limit so looks like time for rebuild of some sort.

I am going to do a leak down test this week to see what exactly is failing .

I take it this would ve my cuase of 180bhp on a td04 at a bar instead of the 220bhp it should definatley be.??

Edited March 23, 2015 by mikey4410

[daniel_g]

Be interesting to see the leak down test results.

180 on a TD04 @ 1 bar is a bit poor but not that shit considering its un mapped.

Rebuild time at 150psi imo, time for a high comp build Mikey.

[mikey4410]

just spoke to a mechanic mate of mine and he says its HUGELY unlikely that piston rings on all four cylinders have gone simultaneously.

more than likely to be timing and or valves.

[daniel_g]

With comp results like that it could be that the rings have just worn equally over time, not necessarily 'gone'. Also valves not seating correctly anymore is another likely scenario. If the timing was out on the belt it would run like a bag of shit and id be surprised if it would even make 180bhp lol. Base timing as you know should be 10btdc.

Also any underlying faults like missfires, faulty knock, blocked fuel filter, fpr not set up correctly, etc will also cause poor bhp.

Personally id make sure every possible thing is bang on first, then go down the rebuild route.

[morgey]

Did you do the comp test hot And WOT?

I did a comp test on my 20v and that only pulled 155 +- 5psi (should be circa 190) but that pulled really good figures Considering the results and milage (155kms).

You could always try the few drops on oil method to see if that bumps the results up?

[mikey4410]

thanks for the replys dan.much appreciated.

to give u an idea,when I bought the engine two years ago it was 180 over all four.it was perfect.

its had oil change every 4 thousand miles without fail with mobil fully sythentic, i have had the cambelt of around 4/5 times since doin various things.

it runs beautifully well,starts on the button hot or cold,new entire ignition system,tps set correctly,timings 10°, afrs are bang on and always have been.

and yes I totally agree with you to do checks and leakdowns before rebuilding. timing belt is next up to check.

thanks again for your time :-D

MORGEY ...the test was done wot and full engine temp. thanks for checking though,appreciate it :-D

Edited March 23, 2015 by mikey4410

[AdamB]

I think the minimum before rebuild is 140psi.

A leak down will deffinately show a better indication of engine health.

For a road engine off the top of my head I think maximum leakage is around 12%. For a race motor it's 3% I know that for sure.

[mikey4410]

yeah I knew it was around 150 ish,but for me its gotta be bang on and right so I am going to do something about it.

yeah I am looking forward to seeing what the leakdown shows adam.as for the leakage yeah I read ideally it really shoukd be under 14%.

thanks matey :-D

[_shaun_]

Nice solid starter motor and battey I take it and a good quality tester. if any are weak it might not Have the grunt to turn it over.

Personally I'd get it mapped. You seemed very happy with it before your bhp result. Personal thought is your just looking for a problem because your power figure was under what you expected but in reality the way it's being managed is considered crude by a lot of people and a fair few predicted the lower results. It's a lot of time and money to rebuild the engine to find out its management where the problems Lie

[mikey4410]

yeah starter and battery are in good order.I have very good voltages also etc.

as for the getting it mapped and it not being that bad dyno result,the cars compression is at the limit or service so needs action and the compression being so low is going to cause power loss. it should be a good 210 plus for a td04L @1bar with a fcd. its only because of this dyno run the poor power has come to my attention and I have looked into it and found a fault.

thanks for comments. :-D

[mikey4410]

all the same readings ,150 psi

[patman]

Absolutely gutted for you Mikey mate, once my car was run in I was gonna pop up to see you always had an interest in your car as you know as love the unique stuff you have done to it

[AdamB]

yeah I knew it was around 150 ish,but for me its gotta be bang on and right so I am going to do something about it.

yeah I am looking forward to seeing what the leakdown shows adam.as for the leakage yeah I read ideally it really shoukd be under 14%.

thanks matey :-D

Are you using an FTE motor or an FE mate? For an FE that is definately low.

Have you whipped the sump off by any chance? Ever had the headgasket replaced?

Reason I ask is there could be a possibility of some forged pistons in there which will lower peak cylinder pressure a bit.

[mikey4410]

its a proper fte matey,yeah tiz on service limit

headgasket I have done as a precaution last year and stocker went on to replace the stocker headgasket. defo all standard inside man

as I say above when I bought engine it was 180 over all four as I did the test personally. theres no way the rings have gone in two years of me over maintaining the car and using the best oil.

gotta be up top or timing of a tooth im sure.

[daniel_g]

Try another gauge, you might be sending yourself on a wild goose chase

[mikey4410]

yeah cheers for advice ,good shout. thanks for all ure help .

[Phil]

i wouldnt worry about results being on the low side so long as they are all similar.

if one was way low id worry.

Drive on, and get it mapped.

Phil

[Mike@TD.co.uk]

i wouldnt worry about results being on the low side so long as they are all similar.

if one was way low id worry.

Drive on, and get it mapped.

Phil

This...

150 over all four is fine.

Thanks

Mike Jones

Tuning Developments Ltd

[AdamB]

i wouldnt worry about results being on the low side so long as they are all similar.

if one was way low id worry.

Drive on, and get it mapped.

Phil

It's not strictly true, you could have a motor with 80psi across all four, but does that mean it's a workable and serviceable motor just because all cylinders are equal?

The line has to be drawn somewhere and that's why service limits are in place.

I'm not saying there is or isn't anything wrong with Mikey's motor, it's his car at the end of the day and knows it better than anyone.

Having looked back at your other dyno thread, 180bhp is probably about right for a TD04 @1 bar with only AFR tuning. Very little power is made by tuning with AFR, power is made with ignition advance and since you don't have anyway of adjusting that it's probably quite a healthy figure.

[mikey4410]

cheers adam.I am with you. its gotta be sorted.the service limits there for good reason I guess.

whatever happens I will fix in within the next few weeks. the fact is its not the compression its meant to have and I will sort it.

as yes they are all spot on 150psi on all four,no variation

[Phil]

It's not strictly true, you could have a motor with 80psi across all four, but does that mean it's a workable and serviceable motor just because all cylinders are equal?

The line has to be drawn somewhere and that's why service limits are in place.

I'm not saying there is or isn't anything wrong with Mikey's motor, it's his car at the end of the day and knows it better than anyone.

Having looked back at your other dyno thread, 180bhp is probably about right for a TD04 @1 bar with only AFR tuning. Very little power is made by tuning with AFR, power is made with ignition advance and since you don't have anyway of adjusting that it's probably quite a healthy figure.

cheers adam.I am with you. its gotta be sorted.the service limits there for good reason I guess.

whatever happens I will fix in within the next few weeks. the fact is its not the compression its meant to have and I will sort it.

as yes they are all spot on 150psi on all four,no variation

Look what you gone and done Adam with you not strictly true comment LOL

Its all Mikey has read and now he is going to rebuild his engine!

@150 across all 4 i wouldnt bother rebuilding, Adam wouldn't either.

if you want more power buy a piggyback emanage and fill your boots.

rebuild when you have to or when your going forged.

Phil

Edited March 24, 2015 by Phil

[mikey4410]

no no no.lol

I have taken all comments into consideration,I have read on a few occasions online that toyota handbook says about 150 being service limit.

the cars running lovely and always has done.just needs a freshen up I guess.

theres more investigating to be done before any rebuild or disassembly.

:-D pmsl

[jayc-glanza17]

Agree with Phil on this mikey

And I believe Adam is correct 140 is the service limit.

If you are really worried, whip sump off and see if and remnants of rings in sump.

plus take the result with a pinch of salt,

[AdamB]

Look what you gone and done Adam with you not strictly true comment LOL

Its all Mikey has read and now he is going to rebuild his engine!

@150 across all 4 i wouldnt bother rebuilding, Adam wouldn't either.

if you want more power buy a piggyback emanage and fill your boots.

rebuild when you have to or when your going forged.

Phil

Haha always subject of controversy my friend

Certainly right, I wouldn't go splashing out a rebuild because of 150psi. Infact I will probably go as far as saying providing the engine has maintained good oil change intervals, the leakage will be most past the valve seats.

[mikey4410]

yeah my car has fully synthetic mobil oil every four thousand miles,is ALWAYS warmed up and cooled down.

I cant see rings wearing from 180 down to 150psi in two years being treated so well.I just cant.