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Automotive Equipment-auto shop machinery and equipment- 4-5 gas engine analyzers or analysers.

New and used engine analysers.

Engine analysers have been with us for a long long time, and it is only lately that they have measured 5 gas emissions.

If you have a workshop and are considering buying an analyser, there are quite a few things to consider.


  • The best of these new machines range upwards of $4,000 each with 4 or 5 gas capacity.
  • All the latest ones will take the fifth gas module, but it is not always included.
  • The central gas analyser at the heart of the machine is only made by 2 manufacturers and quality of these units does not vary even in the cheaper engine analysers
  • The cheap Chinese ones have a pathetic screen card.
  • Some machines are more robust than others.
  • All analysers need a new C02 module annually.
  • A new C02 module fitted varies between 2 and 3 hundred dollars on average.

All this in a small case.

This is the shape of things today. A new Coda 5 gas engine analyser.

This is the shape of things today. A new Coda 5 gas engine analyser.


Portable 5 gas analysers.

There are a huge number of new makes and models of gas analysers on the market today and many of them are very good quality too.

The very smart briefcase type that has all the connections tucked away until needed is a great way to go.

Quality units are not cheap though, so be sure you can see a return if you are going to pay out for one of these units.

The Coda opposite is a fine example of high quality in these briefcase sized units.

We have used these, sold them new and used. They are reliable and sturdy.

No crappy screen on these, you can still see it when it faces the light, or from where you are working on the car, unlike some other gas analysers.

I find it makes a huge difference to doing tune-ups if you don't have to keep the machine next to you so you can read the screen.

A few of the smaller hand held ones have lousy screens.

The Sun Interrogator. It speaks!

The Sun Interrogator. It speaks!


These are also a top analyser and many are still in use today

These are also a top analyser and many are still in use today

Other engine annalysers.

Although a good experienced mechanic may be able to analyse many engine fault with a straight gas analyser, some prefer more tests to drill down to where a problem may be, and older model autos require readings such as dwell angle to be checked.

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I know many mechanics who get great results with gas analysers that are very old but include many more tests as well as omissions.

One example of a fine old machine that will do most anything is the Sun "Interrogator"

This is a big machine on wheels and does take up a fair bit of space.

The interrogator walks you through it's own self test with a built in voice.

The voice then tells the mechanic which leads to hook up and where they go.

Like many early full engine analysers like this, the gas module forms a small part of what the machine checks and many workshops have one of these as well as a modern 4 or 5 gas analyser.

All the test are spoken as completed as are the results, and a printed record is produced for the customer.

If buying one of these machines remember if it has been kept in top condition it will have receipts for annual calibration and C02 module replacement. Watch your step. A bit like buying a used car!


The Allen DEA

You will still see these old Allens in good workshops today. Although the plastic cases were a bit easy to break, the Allen is mechanically and electronically very good and many have survived.

The huge filters on these older machines allowed them to work hard and long with few service intervals.

A very popular machine when it was produced, Allen made a lot of top quality diagnostics and analysers and have a reputation for high quality results.

You can still buy a fully refurbished one of these at the right price in America. I have refurbished and sold them in Australia and know they are reliable if kept serviced. I sold many of these without one problem.

When buying an Allen make sure you get the 4 gas analyser model, as they all look the same, except the one with the analyser has a smaller toolbox.

Small older analysers

Horiba 4 gas. Still a useful 4 gas, but hard to get mirrors for at least in Australia.

Horiba 4 gas. Still a useful 4 gas, but hard to get mirrors for at least in Australia.




Tony Petselas on January 04, 2020:

Hello there,

I have a Allen SEA that desperately needs repair.

Can you help please?


Flocar on September 16, 2014:

I have a Vane Engine Analyzer 3090 from the late 1960's. It looks good sitting in my workshop. But as I have quite a few cars from that era I would like to be able to use it. Unfortunately it doesn't have an instruction manual. I would also be keen to get a circuit although I guess that is unlikely. I realize that some operations are logical but some aren't particularly as I don't know what works or what is just plain faulty.

Anwar Malik on June 28, 2013:

am useind sun engine analyzer MEA1500, I want to change its logic board

due to inactive, if some body help me find its logic board from where to purchase?

cubflyer on March 16, 2012:

does anyone have a hose routing for the 4 gas as my hoses have all started breaking and i have lose ends every where,ihave a mea 1500 i whould like to put back into service as i am working on alote of older cars now Thanks cubflyer

earnestshub (author) from Melbourne Australia on June 17, 2011:

Hello Waqar Ahmed.

The Sun MEA has a standard gas analyser unit which is the same one as used in most analysers around the world. The Sun is very repairable. In Australia we have plenty of technicians who can fit a new CO2 unit and service the analyser.

The Sun needs to be services regularly.

You should be able to have it repaired in Pakistan, I know several technicians have gone back to Pakistan from here, in fact one of them worked for me.

I have never had a Sun MEA cost more than a few hundred dollars to refurbish.

Waqar Ahmed on June 17, 2011:

dear sir my name is Waqar Ahmed from Lahore Pakistan i m search your web site please solve my problem me and my elder brother run an auto work shop we install sun engine analyzer MEA 1500 since 1989 in this work shop worked as environmental program after 7 years analyzer make malfunction we repair the analyzer and run work shop in short last two years the analyzer is out of oder please help me for a second hand analyzer or if repair it please send me advise for parts on my email address ( thanks with best regards God Bless you Waqar Ahmed.

earnestshub (author) from Melbourne Australia on February 13, 2011:

Robert it does not look much like a bottle top I guess. it is milky white and about the size of a soft drink bottle top. As I recall it is on the bench. I will see if I can remember where it is. It's been a while since I services one, as I had a top technician who could do it better than I could, so I only did a few of these myself.

robertxx from oxford england on February 13, 2011:

so i cleaned the cabinet ,and alls well ,apart fom that pesky gas bench .

i did find a hose that was hard and broken on the bench pump ,it went to a grey plastic low flow sensor , and had a weird crimped part in it , i replaced it with a normal pipe ,and tested , but i realize now it needs the crimped part ,although , on testing , i couldn't feel any floy into this low flow sensor . i'll stick a threaded bar in the pipe which may simulate a crimp .i

could not find any bottle top looking device ernest ,,is it actually on the andros gas bench itself ?if its on the end of the bench ,that's a bit innaccessable under the cabinet ...the bench only slides out about half its length . i can just see something white on the end of it .


robert .

earnestshub (author) from Melbourne Australia on February 08, 2011:

That is even more than expected. I reckon they must have had it blessed by the pope for that price!

The sensor is clear in color or off white.

robertxx from oxford england on February 07, 2011:

okey kokey , ill have a look for a small bottle top .

so far quotes for a calc bottle are, smallest available ,110 litres, for 150 quid think ill mail them back and point out i don't want to bathe in the stuff !!!

earnestshub (author) from Melbourne Australia on February 07, 2011:

The C02 is a small plastic capsule about the size of a bottle top. It should be marked as a C02.

You do need a calc gas bottle. My bad, I forgot to mention the bottle! Your questions are fine. If you clean or replace filters and the C02 it should come up all shiny like a new pin.

robertxx from oxford england on February 07, 2011:

thanks ernest,

stupid q of the year (hey ,its only february)what does a co2 sensor look like ??oh ,and don't i need a cal gas bottle ernest? (ok 2 stupid q ! )

earnestshub (author) from Melbourne Australia on February 07, 2011:

Nice news Robert! Glad to know the old girl lives on. It probably just needs a C02 sensor and a filter clean to have the 4 gas up again.

You can probably finish the job yourself. Don't forget to check in the cabinet for a spare C02 unit!

robertxx from oxford england on February 07, 2011:

wel hot mega damn !!!!! it works oh yes !! ,,cleaned the boards and spayed them with the pcb cleaning stuff i got from maplins this morning(fun drive in turbo mini )and joy and wonder all functions ..


apart from the gas bench which is in the usual state of ''not calibrated '' and ''call service engineer '' which they all seem to fdo .so no 4 gas pooh ,but rest ok yay.



earnestshub (author) from Melbourne Australia on February 06, 2011:

That explains a lot, the poor old thing has been too cold. A warm rug and a rest by the fireside and it will be pumping out info again.

I find not many machines like the cold much. It interferes with their electrons. lol

robertxx from oxford england on February 06, 2011:

ahhh isee , for some bizarre reason i thought you were on the same time as my girlfreind in vancouver , i know i know i'm a numpty !lol,,im in southern england near oxford in the coutryside ..maybe a bit far ?lol

earnestshub (author) from Melbourne Australia on February 06, 2011:

I don't run the shop anymore, I got out two years ago. My tech is in Melbourne Australia. It's only 8.30 pm here mate, I don't go to bed that early!

I reckon your ideas are pretty good.I dunno what your weather is like, but sometimes a hair dryer can bring one back to life, or half a day in the sun. Good luck with it. Where are you by the way? If you are in the USA I may be able to help.

robertxx from oxford england on February 06, 2011:

blimey earnest ...shouldn't you be in bed ???

my situation is very very strapped for cash , im ressurecting my sun ram 12 chassis dyno ,and built a sound proofed garage so i can start testing and designing again ,so spending is a problem ! . i thought i may wait for the capacitors to discharge in a day or two ,then hoick out the boards and clean them with brake cleaner ,then search for a bad joint . i temp tested the components with a ir gun and nothing seems wonky there .

the pattern of behaviour suggested a power supply problem ,so i checked the incoming supply bang on 239 v and 49.98 hrz .so fine,also the scope carries on fine although does do a bit of a ac waveform when the other screen is having its fit . .it'll flash a screen of little smiley faces or hashes ,and then freeze . turn it off and on and it'll go further and some times get to full operation ,.other times it will click while booting and restart completely .. is your sun chap available on long distance consult ?;0


robert .

earnestshub (author) from Melbourne Australia on February 06, 2011:

Robert, I would be inclined to pull in a technician if you can still find one, and give the old girl a birthday. It doesn't sound like it has much wrong with it, so as usual it will be a matter of finding the right technician. I had a great one, who can sort a 1500 out very quickly. As you would know, there is not much wrong with the 1500, and it will continue to do the job for years if you drop a new CO2 sensor in and find the open or intermittent circuit. They have a very good scope and the machine was well made, so fix if under $400 or say 250 quid. including filter and sensor service would still be good value. You may have to drop a new or updated card in it.

robertxx on February 06, 2011:

earnest , thanks for the variuos hubnesses i just found ,ive found that if you try a consistent wailing keening soft of sound it disturbs a parrot to the extent that it forgets its own vocabulary .

im just about to torch my long stored mea 1500s tester ,which has an epileptic fit during warm up and siezes the screen .then i turn it back on and it teases me with going right through calibration back to warm up and then ,at 14.99minutes ,freeezes again .

befroe i stored it it seems to be fine on a breif test ,so its either been dry jointing while stored or i rolled it too violently and its fractured somethng intermittently .

an you help with advising the best method of immoliation for it ,or do you think i should attempt repair? nothing smells burnt ,and the occiloscope continues working whatever .


robert .oxon uk .

earnestshub (author) from Melbourne Australia on January 29, 2011:

Abid, I would thoroughly recommend the Coda. Quality all the way and very accurate, low maintenance unit.

Abid on January 28, 2011:

i want to buy this Portable 5 gas analysers


Hello, hello, from London, UK on August 26, 2010:

Very interesting but more for my son. Thank you.

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