Customer Pre Booking Checks 1.8T 20v

“DO IT RIGHT DO IT ONCE” is the best mantra you could ever hear from any tuner.

Unfortunately you will find many tuning companies big or small all willing to flash a map your car – without knowing or checking the condition or health.    These tuning companies and there post tuning experiences tend to end up as negative, and there customers having to pay out £1000s to fixed damaged or blown engines which could have been avoided.  These tuners are just happy to take your remap money and wave you off on your merry way with there fingers crossed hoping all will be OK for you.

We will only start tuning and take your remap money once we are happy with the car, if we are not happy to tune your car then we wont take any risks for the sake of £250-£300 in our pocket.  Its hard for any company to turn money away which customer are willing to hand over, but we know if we did tune unhealthy cars then it would cost you the customer much more to put right and it will put a huge fuck off dent on the great R-Tech brand reputation.  We would rather you use the remap money to fix the car not blow it up.

So our personal mantra here at R-Tech is “Performance Tuning Without Compromise”


This 1.8T 20v  support page will help you make your tuning experience go a slick as possible, so you get it right first time and you can maintenance and look after you own car prior and after a tuning session.

The biggest factor to tuning a 1.8T engine is the hardware, the hardware will determine the final performance output post tuning, it will also be the difference between having a car with post tuning issues or a car which never has issues and runs sweet as a nut for the next 100k.

The most annoying thing for us is people jumping on to the R-Tech bandwagon,  who just buy a car  and bolt on a few parts and not even knowing the basics about there engine.

A question we always ask when the customer first brings there car in to the workshop is “When did you last check your oil”  if the reply is ” never”  “I have never lifted the bonnet” or “I didn’t known I had to” or “It was only serviced 6 month ago” or ” my mate with a 700hp EVO said it would be OK as the oil light aint on”  then alarm bells start ringing!!

The answers we are expecting are common sense based answers, “I check it every weekend and I am using the correct oil recommended for a tuned engine” or the best one ” I did an oil and filter last night as I knew I was coming for tuning so wanted the car best it possibly could be”  these answers are music to our ears.  With the correct anwer feel confident to open the bonnet and not finding a mess which deems the car unfit for tuning and unfit to be running stock power because of a huge list of ignored common faults.   Another one is ” When did you have the fault codes in the ecu tested last”  if ” Never I have not got a light on the dash yet” then we just headbutt walls and cry.

Our waiting list is around 4-5 weeks for remaps which gives you plenty of time to get your car checked and into a condition so it can be custome tuned on our rolling road without any issue.  For the staff at R-Tech it is sad to see customers drive off with there tails between there legs because they have been refused tuning due to a list of common avoidable issues.

We will be checking everything possible prior to the car going on the ramp to make sure its safe to tune, we will check oil, fuel filter carry out smoke tests ect, so we can see if you have missed anything. The results we are after should reflect what you have been reading on this guide and there will be no issues at all.

The most annoying part of tuning for the customer and the tuner is having a car which is not fit for  custom mapping due to hardware faults.  This ends up costing you the customer lost time, fuel money and the booking slot fee. There is only one person to blame an that is you the owner.

It is your responsibility to “try” and bring a fit and healthy car to your tuning session.

Below is a quick guide to help you check over your car to find and eliminate common issues which will compromise the tuning session.

If you think your car has a strange issue or something don’t feel 100% then please call us asap so we can assist you and help you save time and money, please do not turn up on the day of mapping and point out these issues as they could be something major could end up with the remapping session being refused, you will lose the booking slot money you paid.

The basics needed cars of all mileage :

  1. Decent fuel 99Ron Vpower or Tesco not 95 ron,  if you run 97 ron then expect much less power from the mapping
  2. Recent oil and filter using quality 5w/40 fully synthetic oil
  3. Coil Packs are common to fail during or post tuning,  If you have original, old, mixed or non oem coil packs the get a new oem set fitted
  4. Spark Plugs, healthy fresh spark plugs running a heat range colder will be needed > part number #
  5. Fresh fuel filter
  6. Road Legal tyres

Car with high miles 100-120k+ issues which cannot be seen or found prior to tuning but common sense to change to avoid not getting mapped on the day.

  1. Fuel pump,  the most common issue for not begin able to tune a car with over 10000 miles, is the fuel pump, just fit a new oem pump don’t take the risk on hoping is will be ok because 95% of the time the pump will be weak and will fail to flow fuel safe for the additional power.
  2. Clutch Plates, if  you are wanting decent torque and strong power from stage tuning then we recommend fitting a new oem clutch because around 70% of the time a worn clutch with high miles will struggle with the additional torque. This is not too much of an issues as we can reduce the torque on the day, but nothing to say it wont slip a few weeks later.

“Basically the higher the miles the car has the more issues you may find, not matter how well serviced the car has been.”


Now we will start with the most common issues you will run into.

Issue 1 = Leaking / Split / Collapsed PCV System 

The PCV system (Positive Crank Ventilation) is a series of pipes and valves which connects the intake pipe – inlet manifold – crank case – cam split in 90 below the IMcover. In idle the gases from the cam/crank as sucked straight into the inlet manifold and burnt off, once driving under load on boost the boost pressure closes as one way valve under the inlet manifold the cam/crank gasses are then vented onto the turbo intake pipe, this allows the manifold to be air tight to produce the boost levels requested by the ecu.    It is very common for the pcv rubber hoses to go soft a split which causes the boost pressure to leak and be bled off, which causes the turbo and turbo boost control to work near enough flat out just to make the factory power.  Most of the time this fault will go unnoticed and the in stock form will seem like its ok and can be clear of fault codes.  But once tuning with  this issues of a leaking pcv the mapping can be chucked a mile out the fuel trims will be wrong the turbo will be over spooling and the car will be a moon mile of the tuned power it should be at, in fact if its leaking bad the car will make no more power than standard power.

Below is a pictures of common issues with the 1.8T 20v PCV system.  A quick basic inspection which you can do is look around the pipes for signs of leaks, the leak tend to stand out buy showing signs of wet oil deposits around them or the area they are situated in.  Where ever you see wet oil deposits on a 1.8T engine is a sure sign of an oil leak or a boost leak and will Breather_hose pcv splitneed investigating and fixing asap.  If you do find wet oiled pipes under the inlet you will need to look on the bends of the pipes where you will find splits / holes its these splits which you need to fix by, 1 replacing the pipes , but this will start to become very expensive due to one pipe being faulty its inevitable other pipes will split soon after or when disturbed by trying to remove pipes in the same location.  Option 2 is to fully remove the PVC systems and all pipes linked to causing issues, this way you know you wont have any future issues and will cost a tiny fraction of what it costs to replace the pipes.   We recommend getting rid of the PCV just to save hassle.

Parts number for the common items which fail










Issue 2 = Fault stored codes.

Modern cars have a complex but dumb on board self testing diagnostics sytems.  We say dumb because you could have 100s of stored fault codes and logged issues in the ecu memory but the orange engine management can remain off.  So basically because you have no orange warning lights on the dash don’t mean that your car is fit, healthy and fault code free.   To save being turned away during a mapping session we tell customer to try and get there ecus fault code memory read prior to the tuning slot.  You will need to find a local garage who have a obd code reading system which is VAG specific which can log into the full ecu memory and extract all the codes.   Please note most obd diagnostic tools use a generic obd protocol which is common for every modern ecu since 1995, these tools will NOT read the unique VAG related codes and can show there are no fault codes, but when plugged in with a VAG obd tool there could be a hand full of codes and issues stored.   It a good idea and cheaper option to buy your own VAG based hand held diagnostics tool to keep in your glove box , this way you can keep on top of your car post mapping and make sure your car is clear before the tuning session.  You can buy basic VAG hand held code readers from £50 from ebay which will read all the memory areas and codes.

Once you have read your codes but one of the unlucky ones who has codes stored you will need to write them down along with the code detail which the obd tools show,  firstly you should ring us and tell use the codes you have, at this point we can tell you if they are phantom codes which just randomly pop up, or if the are codes which are serious and need attention straight away.  Most of the time we can help you fix the issues over the phone.   Once you know where you are with the fault codes and/ or have fixed the issues then at this point you can clear the codes but keep checking they don’t come back instantly or a few days later.  The idea is for you to make sure the car is fault code free and health for the day of your tuning session.  We will bend over backwards via email or over the phone to help you get your car fit.  You could also pop into use prior to your remap session so we can give you a free basic health check and fault code reading, which then will give you time to resolve the issues if any before your actual booked date.

Issue 3 = Old Fuel filters / weak  failing fuel pumps

The limiting factor to tuning is the fuel flow and volume,  its simple as not fuel no power.  Again you could have fuel flow issues and running lean on a standard car but  and it may seem ok to drive but as soon as the map starts for ask for more power major issues can pop up straight away.

The common serviceable item which gets missed or over looked is the fuel filter located underneath the car infront of the drivers side rear wheel. If it looks old or rusty then replace asap.  Even if the filter don’t look too old but you dont know how long its been on the car for the sake of £10-£20 its worth getting replaced with a new fresh filter just in case.

Fuel pumps are electric motors and over time the become lazy and struggle the provide fuel higher up in the rpm range, its rare for this to be an issue at stage 1 engines, more common an issue which pushing on to stage2 power.   The issue hear is its imposible to tell how good or bad a pump is without starting to tune the car and actually running into the flow issues.  To avoid this you can be preemptive and fit a new fresh pump if you are planning tuning above stage 1 and your car has more than 100-120,000 miles on the clock.


Issue 4 = Cam belts incorrectly fitted

There are plenty of bad cowboy mechanics out there doing crap jobs, there are also a lot of bloody good mechanics out there but due to how tight and fiddly the 1.8T 20v is its easy for the best mechanics to allow the belt tensioner to take up the tension during belt installation and  cause the belt to be incorrectly fitted by being a tooth or two out.   If the belt is a long way out of sync the ecu will pop up a fault code warning you there is something not right with the settings between cam and crank pulleys.

Codes you might see: Camshat A (Intake):  Setpoint not Reached  or  17748 / P1340 cam position senor / engine speed sensor incorrect correlation.   This a sure sign of a major issue.

Its very common for car to come in fault code free but have the cam belt fitting wrong the only way t make sure is check the timing makes visually. This 1.8T cambelt insallation guide link will help you check and eliminate any timing belt issues.


Issue 5 Coil Packs

It is recommended to have a fresh new set of oem coil pack fitted prior to tuning as ir is very common for old coils to fail straight after tuning

Issue 6 DV Diverter Valve

Old oem DVs are prone t being split or splitting there rubber during a tuning session, it is recomended to have a new one fitted prior or during your remap session

Issue 7 MAF Air Flow Meter

A sign of a faulty maf is poor mpg, rough running, flat spots lack of power ect.  If you have a car with high miles 80k+ and you are running the original maf or you dont know how long the maf has been on the car, then its a good idea to get an new one fitted.

Issues 8 smoking / oil /

Cheap poor oil will cause the car to smoke and rattle more than it should if this is extream then we will not be happy to tune the car,  prior to tuning your 1.8T engine we advise minor engine service new oils and filter, use 5w/40 Quantum Platinum oil from the main dealers along with a genuine filter this way you know the components will be well lubricated and cooled with the best oil for your car.


If you have VCDS / Vagcom and have the ability to log you car.

Having the ability you log your ecu while driving will help you spot any other underlying issues.

Follow this link for a guide on how to log using VCDS/ Vagcom >

Before doing logs or clearing  you will need to make a not of your fuel trims on blocks 032,  while on idle there will be two numbers which are formatted like this example   -4%   +11%. and then the cam  shaft set point on blocks 093 which may look like -4kw.    please add these readings to the email.

You will need to do the following engine logs and then email them to us to check once you have made your booking date.

In the email please include booking time and date , reg number and exact  car spec with mods if any, and if you are feeling running issues  please explain in detail what the car is doing so we can review the data correctly for you to see if we can help pin point issues.

Carry out log runs with engine upto full temp in 3rd or 4th gear from 2000rpm to the rev limiter at full throttle on one sweep (when and where its safe to do so)

Log Set Fuel  = 001 002 031

Log Set Timing 003 020 114

Log Set Boost = 114 115 001

These logs set can also be set to us post tuning is for ever run into issues, I may help you with fault finding or just a piece of mind.