Nissens Automotive focuses on the air conditioning condenser
Published: 25 April, 2022
Nissens Automotive offers a wide range of replacement A/C components. Alongside Genuine Nissens parts, the company has a vast array of technical information it makes available to technicians, and it looks to highlight areas of importance, such as the A/C condenser.
Focus on the condenser
A faulty condenser, even if it is still partially working, can lead to severe A/C problems and sometimes result in damage to, or even seizure of, the compressor. Compressors are costly and replacing one will take the vehicle off the road as the rest of the A/C system will need to be examined and flushed, and the oil/gas refrigerant mixture replaced.
The condenser is typically attached to other heat exchangers in the engine compartment and its role is to ensure that the state of the refrigerant changes from gas to liquid, which happens through condensation. The airflow through the condenser’s fins enables this process by extracting the refrigerant heat and exchanging it with the ambient air.
Mechanical damage
Mechanical damage is often ruled out as a reason for reduced system performance or compressor failure because leakages and surface perforations are generally considered the most common causes. However, even light mechanical deformation of the condenser tubes and fins can result in severe system performance limitations.
Corrosion
As one of the A/C components placed closest to the elements, the condenser is exposed to harsh conditions, particularly salt spray, which increases the risk of corrosion.
Blockages
When impurities develop in the system, the thin channels of the condenser will quickly clog. This can restrict the refrigerant flow, eventually reducing the unit’s ability to exchange heat. In most cases, this will subsequently cause overpressure in the system, which is very harmful to the compressor.
Condenser tips
1. Always handle the condenser properly and do not disregard any light damage on its surface. If the tubes or fins are visibly damaged, replace the condenser.
2. Irrespective of the primary reason why a vehicle visits the workshop, technicians should always carry out a visual inspection of the entire A/C system to check for leaks of oil residue on component surfaces, around joints and couplings.
3. Surface inspection of the condenser can save expensive system and compressor repairs. So, any signs of corrosion or leaks on the condenser surface must be considered as serious threats to the efficiency and operation of the system. Pay particular attention to the bottom part of the condenser, where tubes and fins are most exposed to humidity and aggressive salt spray. If there are any signs of leakage or missing/deteriorated fins, replace the condenser.
4. When replacing the condenser, choose one with corrosion protection applied, as this will considerably prolong its lifespan.
5. To keep the condenser in good condition, the receiver drier must always be replaced during a compressor replacement, if the circuit has been exposed to ambient air, or the system has run empty due to leakages.
6. When performing a system flush after a compressor breakdown, make sure that no flushing agent residues remain in the system afterwards and always use the recommended oil and additives, and in case of doubt, replace the condenser.
For more information, visit: https://nissens.showpad.com/share/TolT49laOCRcAZti0mE8q
- Nissens introduces oil cooler assemblies
Nissens Automotive has added plug-and-play oil coolers to its range that come with additional components such as an oil filter and housing. The new assemblies are part of Nissens Automotive’s First Fit programme, so they are supplied with gaskets pre-mounted on the unit to help save time during the installation process. The extension of the oil cooler assembly aftermarket programme includes 13 new items in addition to an existing range of 23 products covering more than 220 OE references.
nissens.com
- Blue.on from Hengst SE
The Blue.on oil filter system, from Hengst SE has been developed as an alternative to the classic spin-on oil filter. The system consists of a housing and pipe designed as lifetime components with integrated filter bypass and return valve. Added to this is the fully incinerable filter element, the only component that still needs to be replaced when the filter is changed. In addition, Blue.on saves up to 90% of the waste mass produced by conventional spin-on oil filters, thus making an important contribution to environmental protection.
- Klarius: engine maintenance and service fluids
Klarius Products' range of automotive maintenance products has grown with the addition of new engine fluids. Klarius engine flush is designed to purge sludge and carbon from the engine prior to adding new oil. Suitable for the oil systems of either petrol or diesel cars, the flush helps to stabilise cylinder compression, extends the service life of exhaust devices and reduces emissions while lowering fuel and oil consumption. Petrol System Cleaner removes varnish and gum from the fuel system. When added to a half full tank, the fluid clears EGR valves and tackles carbon deposits. Diesel System Cleaner is used in the same manner, helping to clean injectors, compression rings and valve seats. Completing the range is DPF Regeneration Aid, which is formulated to allow soot burn off inside the device at lower temperatures. This is useful for diesel vehicles that only conduct short journeys where high regeneration temperatures aren't typically reached, it keeps the DPF filter clear to prevent clogging and power loss.
www.klarius.eu
- New hybrid/EV HVAC video from Nissens
With the growing popularity of hybrid and electric vehicles, technicians need to understand that there are differences within their heating ventilation and air conditioning (HVAC) systems, when compared to vehicles powered by traditional technology, and although contamination of the refrigerant and lubricant mixture can be an issue for both, the flushing process also varies.
- A buffet of errors
I have always focused on topics that have developed through our workshop, the main reason for this is authenticity and integrity. However, it is not always possible to be fortunate enough to have topics with enough content for publication. So, this month we are going to have a banquet of multiple stories of interest where you can spin the table and pick your favourites.
First topic
An Audi S3 came in for a MIL light and poor running complaints. Initial serial interrogation concluded camshaft correlation errors. This has significant concerns with this 888 power plant, as it has variable inlet and exhaust control as well as exhaust valve lift. This is a very powerful and usually competent engine, but unfortunately the vehicle was purchased recently with a known poor service history. This is an absolute no-no with today’s technology. Having conducted a basic health assessment, and noting actual and specified camshaft position errors, it was decided to replace the oil and filter. I must add here that it ran much worse afterwards.
Historical experience has shown problems with chain jumping and oil filter cartridge collapse. This engine employs a variable displacement oil pump providing 1.8 bar at low speed and 3.8 at higher load. It is also PCM-mapped. I am not a fan of such a low oil pressure especially on crank start. My Seat Cupra has on several occasions displayed slight chain tension noise on start up. Bear in mind I replace the oil every 3,000 miles, and it has only done 18,000 miles.
Additional thoughts should be given to Stop/Start; All engines will suffer gravitational oil drainage when stopped. We are now increasing this multiple times. Not a good idea really. We have also seen oil filters collapse shedding filtration media particles into the oil galleries.
The timing cover was removed, visual evidence shows surface bearing damage to both the cams and alloy cover. This evidence confirms both a boundary layer lubrication failure and metallic swarf erosion. In my opinion this is sufficient evidence to reject the entire engine, subject to a total strip-down. Please refer to; Fig.1, cam sprocket and chain; Fig.2 cover housing; Fig.3 Parts assembly.
The vehicle is still enjoying an elevated position awaiting my report for the insurance company, which requested to know what caused the problem.
I have penned many reports and have prevailed in all my expert witness cases, and smell another one here, or it could be the beef noodles and bean sprouts?
Second topic
Next, we have an AUDI A6 2.7 CRD presented to us as a trade-in into a Vauxhall dealership. The problem is that it is cranking with intermittent no-start. Initial checks were carried out showing a DTC, ground short to power on the in-tank fuel pump relay. I am often amused with this description, as if it was taken literally there would be smoke and probably fire as the loom fuses together rather quickly.
Please refer to Fig.4 relay location r/h. Time to call Diagnostic David. Why the definition? Well, we have three Davids at ADS. Diagnostic David bridged the relay 30-87 terminals in order to run the pump and the vehicle started every time. He then conducted wiring integrity tests between the PCM and pump relay focusing on terminals 86-85. No problems here, power was present from supply right back to the ground control circuit at the PCM. The obvious conclusion an internal PCM ground switch error? This is where you MUST take a pause? Why? Because you have discovered the symptoms NOT the cause. David then exposed the edge connector between the loom and PCM. Please refer to Fig.5; Oil on PCM socket. David elected to expose the board in the PCM and visually check for component damage. Visual evidence shows blister damage to a controller chip suggesting excessive load.
Having discovered oil on the edge connector we now need to prove the cause. So, we are looking for capillary invasion through the loom from a component with access to oil. The usual and obvious components oil switches showed no oil invasion on the sockets.
In fact, the search proved difficult due to limited access. However, David eventually discovered the path of capillary invasion back to #5-injector socket. This engine variant uses piezo injectors, and to my knowledge I have never heard of or experienced this type of problem. The electrical connector is external from any lubricant, so the problem must be internal from within the portion that is exposed to lubricant.
